TW201640713A - Electrical storage device outer-package material - Google Patents

Abstract

This electrical storage device outer-package material has a structure in which at least: a base material layer; a first adhesive layer; a metal foil layer having a corrosion prevention treated layer provided on either or both surfaces thereof; a second adhesive layer or an adhesive resin layer; and a sealant layer, are laminated in this order, wherein the sealant layer includes a layer formed by a resin composition containing (A) 60 to 95 mass% of a propylene-ethylene random copolymer and (B) 5 to 40 mass% of a polyolefin-based elastomer including 1-butene as a comonomer and having a melting point of 150 DEG C or lower.

Description

External materials for power storage devices

The present invention relates to an exterior material for a power storage device.

As the power storage device, for example, a secondary battery such as a lithium ion battery, a nickel hydrogen battery, or a lead storage battery, and an electrochemical capacitor such as an electric double layer capacitor are known. Lithium ion batteries with high energy density have been attracting attention due to the miniaturization of the portable device or the limitation of the installation space. As for the materials used for lithium ion batteries, metal cans have been used so far, but multilayer films which are lightweight, highly exothermic, and can be produced at low cost (for example, substrate layers) are gradually used. /Metal foil layer / sealant layer structure film).

In the lithium ion battery in which the multilayer film is used for an exterior material, in order to prevent moisture from penetrating into the interior, a structure in which the battery contents are covered with an exterior material including an aluminum foil layer as a metal foil layer is used. A lithium ion battery having such a structure is called an aluminum laminate type lithium ion battery. The battery content of a lithium ion battery, including: a positive electrode, a negative electrode, and a separator, and an osmotic aprotic property such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. An electrolyte solution in which a lithium salt is dissolved in an electrolyte or an electrolyte layer composed of a polymer gel impregnated with the electrolyte.

For an aluminum-layered lithium ion battery, for example, it is known that a concave portion is formed in a part of an exterior material by cold forming, a battery content is accommodated in the concave portion, and the remaining portion of the outer material is folded in half. The edge portion utilizes a heat sealed encapsulated embossment type lithium ion battery. In the exterior material constituting such a lithium ion battery, it is required to exhibit a sealing property which is stable by heat sealing, and it is required to be less likely to cause a decrease in the lamination strength between the aluminum foil layer and the sealant layer due to the electrolyte solution of the battery content.

Then, for example, Patent Document 1 proposes an exterior material including a heat seal layer (sealant layer) containing an adhesive polymethylpentene layer.

Further, as the recess formed by cold forming is deepened, the energy density of the lithium ion battery can be improved. However, as the recess is deepened, it is more likely that fine cracks are formed in the sealant layer due to the skew generated during cold forming, and in particular, it is easier to cause whitening of the sealant layer at the extending portions such as the molded side portion and the corner portion. The whitening phenomenon in cold forming causes a decrease in insulation and causes deterioration of battery performance. Therefore, it is required to suppress whitening due to cracks, and it is also required to suppress whitening due to bending.

Then, for example, Patent Document 2 proposes an exterior material having a heat seal layer (sealant) composed of a high melting point polypropylene layer having a melting point of 150 ° C or higher and a propylene-ethylene random copolymer layer. The layer is an exterior material that exhibits stable sealing properties, heat resistance, insulation properties, and formability.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-245983

Patent Document 2: Japanese Laid-Open Patent Publication No. 2007-273398

However, in the conventional exterior material as described in the above-mentioned Patent Document 2, the improvement in the sealing property, the improvement in the insulating property, and the heat resistance of the sealing portion have been examined. However, it is not considered to be the most in the manufacturing steps of the electrical storage device. Improvement of a severe degassing seal (sealing in a state containing an electrolyte). In the case of the deaeration sealing, since the heat is sealed while the electrolyte solution is contained, the heat during sealing is taken away by the electrolyte, and sealing failure is likely to occur. On the other hand, among the requirements for increasing the tact time of the power storage device, stable sealing (degassing heat seal strength) at the degassing sealing step where heat of sealing is most required is required. Further, in order to improve the sealing property in the deaeration sealing step and excessively improve the heat sealability at a low temperature, heat fusion (oversealed portion) other than the sealing portion, and seal thinning may occur ( The problem that the thickness of the sealing portion is reduced) and the internal volume of the electrical storage device are reduced.

The present invention has been made in view of the problems of the above-described conventional technology, and a first object of the invention is to provide an exterior material for a power storage device capable of suppressing generation of an excessively sealed portion and occurrence of molding whitening while degassing The sealing properties of the heat seal strength associated with the electrolyte are enhanced.

Moreover, as is conventionally described in the above Patent Document 1, In the exterior material, although the suppression of the decrease in insulation due to the heat and pressure of the heat seal or the improvement in the sealing property is discussed, the most severe degassing seal in the manufacturing step of the electricity storage device is not discussed (to include electrolysis). Improvement in the sealing of the liquid state. In the case of the deaeration sealing, since the heat is sealed while the electrolyte solution is contained, the heat during sealing is taken away by the electrolyte, and sealing failure is likely to occur. On the other hand, among the requirements for improving the tact time of the manufacture of the electric storage device, stable sealing (degassing heat seal strength) at the degassing sealing step which requires the most heat of sealing is required.

In addition, in recent years, with the reduction in the size and size of electronic devices such as smart phones and tablet PCs, it is required to reduce the thickness and capacity of batteries mounted on electronic devices. Among them, from the viewpoint of increasing the battery capacity and reducing the cost, the battery exterior material is required to be thinner, and it is also required to be thinned in the inner layer of the insulator. However, in the conventional exterior material, if the inner layer is formed into a thin film, fine cracks are likely to occur in the sealant layer due to stress during cold forming, and the electrolyte penetrates into the crack and is likely to occur after molding. The problem of reduced insulation is such.

The present invention has been made in view of the problems of the above-described conventional techniques, and a second object thereof is to provide an exterior material for a power storage device, which has insulating properties after molding and an electrolyte solution including degassing heat seal strength. Excellent sealing properties.

(first invention)

In order to achieve the above first object, the first invention of the present invention provides a An exterior material for a power storage device having a metal foil layer, a second adhesive layer or the like in which at least a base material layer, a first adhesive layer, and an anticorrosive treatment layer are provided on one or both surfaces in the following order An exterior material for a power storage device having a structure in which a resin layer and a sealant layer are contained, wherein the sealant layer contains a layer formed of a resin composition containing (A) propylene-ethylene random 60 to 95% by mass of the copolymer and 5 to 40% by mass of the polyolefin-based elastomer having a melting point of 150 ° C or less which is a comonomer of (B) 1-butene.

According to the external sealing material for a power storage device, the sealant layer having the above-described structure can prevent the occurrence of excessive sealing portions and the occurrence of molding whitening, and the sealing property relating to the electrolyte including the degassing heat seal strength can be suppressed. Upgrade. That is, the (A) propylene-ethylene random copolymer (hereinafter also referred to as "(A) component") has low crystallinity and good heat sealability, and further blends (B) with 1-butene as a comonomer. The polyolefin-based elastomer having a melting point of 150 ° C or less (hereinafter also referred to as "component (B)") can appropriately improve the sealing property under low heat, and can improve the sealing property with respect to the electrolytic solution, in particular The strength of the degassing heat seal is increased. In this case, when the content of the component (B) is less than 5% by mass, the improvement of the heat-sealing strength of the degassing is particularly insufficient. If the content of the component (B) is more than 40% by mass, the elastomer component becomes excessive, which may result in a sealant layer. The heat resistance is lowered, and the heat sealability at a low temperature becomes too high, resulting in an increase in the excessively sealed portion, and a decrease in workability even during processing. Therefore, by setting the content of the component (A) and the component (B) in the above range, it is possible to improve the sealing property of the electrolytic solution including the deaeration heat seal strength while suppressing the occurrence of the excessively sealed portion. In addition, by copolymerizing (B) with 1-butene The monomer can obtain a good affinity with the component (A), and the occurrence of cracks during cold forming is suppressed and the whitening phenomenon is lowered as compared with the case where an elastomer containing no 1-butene is used.

Moreover, since the outer casing for an electrical storage device according to the present invention can stabilize the deaeration heat seal strength, it is possible to suppress the influence of heat during sealing and to shorten the tact time of the power storage device.

In the above-mentioned (B) polyolefin-based elastomer, the (B) polyolefin-based elastomer preferably contains (B-1) a compatible polyolefin system which is compatible with the (A) propylene-ethylene random copolymer. The elastomer and the (B-2) incompatible polyolefin elastomer which is not compatible with the above (A) propylene-ethylene random copolymer.

(B-1) The compatible polyolefin-based elastomer can impart further low-temperature sealing properties and resistance to molding whitening, and can further improve sealing properties relating to the electrolytic solution such as degassing heat-sealing strength. On the other hand, the (B-2) non-miscible polyolefin-based elastomer can improve the sealing properties relating to the electrolyte such as the degassing heat-sealing strength due to the effect of stress relaxation. By using these polyolefin-based elastomers of the two types of insoluble and incompatible systems in combination, the molding whitening resistance and the sealing property with respect to the electrolytic solution can be improved in a well-balanced manner.

Here, the (B-1)-compatible polyolefin-based elastomer is preferably a propylene-1-butene random copolymer, and the (B-2) non-phase-soluble polyolefin-based elastomer is preferably ethylene- 1-butene random copolymer. The (A) component and the propylene-1-butene random copolymer and the ethylene-1-butene random copolymer have a good affinity, so that the above-mentioned resistance to molding whitening and sealing properties related to the electrolyte can be more balanced. Good improvement. Again, for example when using In the case of an ethylene-propylene elastomer (which is obtained by slightly dispersing an olefin rubber in polyethylene (70 to 80% by mass), etc.), a non-compatible elastomer which does not contain 1-butene is used in a sealant. A clear island structure is formed in the layer, and cracks (voids-cracking) are likely to occur at the interface of the island structure due to stress during molding, and whitening tends to occur. On the other hand, when an incompatible elastomer containing 1-butene such as an ethylene-1-butene random copolymer is used, the interface adhesion in the sea-island structure can be improved, and even if molding is applied Such stress can also reduce the occurrence of whitening.

In the exterior material for an electrical storage device, it is preferable that the metal foil layer and the sealant layer pass through the adhesive resin layer, and the adhesive resin layer contains a modified polypropylene as an adhesive resin composition. Since the modified polyolefin resin forming the adhesive resin contains the modified polypropylene, the (B) polyolefin-based elastomer having 1-butene as a comonomer and the affinity of the modified polypropylene forming the adhesive resin can be obtained. As a result, cracking between the adhesive resin layer and the sealant layer is more suppressed, and a higher inhibitory effect can be obtained with respect to reduction in sealing strength and occurrence of whitening.

Further, in the exterior material for an electrical storage device, the metal foil layer and the sealant layer may pass through the adhesive resin layer, and the adhesive resin layer may be an adhesive resin composition and an irregular structure. Propylene and/or irregularly constructed propylene-alpha olefin copolymers. In this case, whitening due to molding can be alleviated.

Here, it is preferable that the above-mentioned adhesive resin layer further contains a propylene-α-olefin copolymer having an isotactic structure. In this case, since the flexibility of the stress-relieving stress can be imparted to the adhesive resin layer, the heat-sealing strength can be improved while suppressing the decrease in the electrolyte lamination strength (especially resistant). Electrolyte), improve the degassing seal strength. Further, by combining with the irregularly structured polypropylene and/or the irregularly structured propylene-α-olefin copolymer, the whitening phenomenon and the bending insulation resistance can be further improved.

In the above-mentioned exterior material for an electrical storage device, the anticorrosive treatment layer may be provided on at least the sealant layer side of the metal foil layer, and the anticorrosive treatment layer may be selected from the group consisting of a cationic polymer and an anionic property. At least one polymer of the group of polymers, the metal foil layer and the sealant layer are passed through the second adhesive layer, and the second adhesive layer comprises the above-mentioned second adhesive layer The above-mentioned polymer contained in the anticorrosive treatment layer has a reactive compound. In this case, since the polymer in the anticorrosive treatment layer and the above compound in the second adhesive layer are firmly bonded, the adhesion between the anticorrosive treatment layer and the second adhesive layer is improved, and the laminate strength is improved.

In the above-mentioned exterior material for a storage battery device, when the anticorrosive treatment layer contains the polymer and the second adhesive layer contains a compound reactive with the polymer, the second adhesive layer may further comprise an acid modification. Polyolefin resin. In this case, the adhesion of the second adhesive layer to the anti-corrosion treatment layer is further improved, and the solvent resistance of the second adhesive layer is further improved.

Moreover, in the exterior material for an electrical storage device, the anti-corrosion treatment layer may contain a rare earth element oxide and 1 to 100 parts by mass of phosphoric acid or phosphate with respect to 100 parts by mass of the rare earth element oxide.

(second invention)

In order to achieve the above second object, the second invention of the present invention provides a The exterior material for an electrical storage device has a metal foil layer, a second adhesive layer or an adhesive layer in which at least a base material layer, a first adhesive layer, and an anticorrosive treatment layer are provided on one or both surfaces in the following order. An exterior material for a power storage device having a structure of a resin layer and a sealant layer, wherein the sealant layer contains a layer formed of a resin composition containing (A) propylene-ethylene random copolymer 60 to 95% by mass of the (B')-compatible elastomer which is compatible with the above (A) propylene-ethylene random copolymer and/or has no phase with respect to the above (A) propylene-ethylene random copolymer The soluble (C) incompatible elastomer is a total of 5 to 40% by mass; and in the above resin composition, the mass ratio of the (C) incompatible elastomer content to the (B') phase-soluble elastomer content is 0 to 1, and the (B')-compatible elastomer and the (C) incompatible elastomer have a common comonomer component.

The exterior material for an electrical storage device has the sealant layer having the above-described structure, and is excellent in insulation properties after molding and sealing properties relating to the electrolytic solution including degassing heat seal strength. In view of battery safety, the sealant layer is preferably polypropylene, and the (A) propylene-ethylene random copolymer (hereinafter also referred to as "(A) component") has a low crystallinity and a punching strength. It is high and the crack due to the molding stretching is suppressed, and the heat sealability is good. Further, by blending a (B')-compatible elastomer (hereinafter also referred to as "(B') component"), the crystallinity of the sealant layer is further lowered, volume change due to heat shrinkage is suppressed, and cold forming is performed. The occurrence of cracks is inhibited. As a result, the insulation after molding is excellent. Further, when the (C) incompatible elastomer (hereinafter also referred to as "(C) component") is further blended, the sealing property relating to the electrolytic solution, such as deaeration heat sealing, can be further improved. In this case, since the content of the component (A) is less than 60% by mass, the component (B') is The elastomer component of the component (C) is excessively increased, and the influence of the swelling of the elastomer component due to the electrolytic solution is excessively large, and the insulating property after molding is lowered. In addition, when the content of the component (A) is more than 95% by mass, the improvement of the sealing property with respect to the electrolytic solution is insufficient. Therefore, by setting the content of the component (A), the component (B') and the component (C) to the above range, the insulating property after molding and the sealing property relating to the electrolytic solution including the degassing heat-sealing strength are excellent. In addition, since the component (C) forms an island structure with the component (A), it may become a major factor in the crack (pore-cracking) at the interface of the island structure, but the content of the component (C) is relative to (B'). The mass ratio of the component content is 0 to 1, so that the generation of cracks is sufficiently suppressed. Further, since the (B') component and the (C) component have a common comonomer component, a good affinity between the (B') component and the component (C) and the component (A) can be obtained, and the component (A) can be improved. The interface of the island structure is intimate, and the generation of cracks is sufficiently suppressed.

Moreover, since the outer casing for an electrical storage device according to the present invention can stabilize the deaeration heat seal strength, it is possible to suppress the influence of heat during sealing and to shorten the tact time of the power storage device.

In the above-mentioned exterior material for a storage battery device, the (B') phase-soluble elastomer is preferably a propylene-1-butene random copolymer, and the (C) non-phase-soluble elastomer is preferably ethylene-1-butene. Alkene random copolymer. Since the affinity of the component (A) and the propylene-1-butene random copolymer is good, and the affinity between the propylene-1-butene random copolymer and the ethylene-1-butene random copolymer is good, The affinity in the interface of the island structure is further improved, and the generation of cracks during cold forming is more suppressed, and the insulation after molding can be further improved. For example when using an ethylene-propylene elastomer In the case where the olefin-based rubber is finely dispersed in polyethylene (70 to 80% by mass), such as a non-coherent elastomer which does not contain 1-butene, a clear island structure is formed in the sealant layer. It is easy to cause cracks at the interface of the island structure due to stress during molding. On the other hand, when an incompatible elastomer containing 1-butene is used as in the case of an ethylene-1-butene random copolymer, the interface adhesion in the sea-island structure can be improved, and cracks can be caused. The generation is more suppressed, and the decrease in insulation which occurs when the electrolyte penetrates into the crack is more suppressed.

In the above-mentioned exterior material for a storage battery device, the (B') phase-soluble elastomer is preferably a hydrogenated styrene-based elastomer, and the (C) non-phase-soluble elastomer is preferably a styrene-based elastomer. Since the affinity of the component (A) and the hydrogenated styrene elastomer is good, and the affinity between the hydrogenated styrene elastomer and the styrene elastomer is good, the affinity at the interface of the sea-island structure can be further improved. Moreover, the generation of cracks during cold forming is more suppressed, and the insulation after molding can be further improved. In addition, since the styrene-based elastomer is excellent in flexibility and elasticity, stress such as molding can be alleviated. Therefore, the occurrence of cracks due to stress during cold forming can be suppressed, and insulation after molding can be achieved. More improvement.

In the above-described exterior material for an electrical storage device, it is preferable that the sealant layer is formed of a plurality of layers and the plurality of the sealant layers are formed, and the sealant layer has the second adhesive layer or the The layer on the opposite side to the surface of the resin layer (hereinafter referred to as "the innermost layer of the sealant layer") is a layer formed of the following resin composition, and the resin composition contains the above ( A) a propylene-ethylene random copolymer, and does not contain the above (B') phase-soluble elastomer and the above (C) incompatible elastomer A resin composition of the body; or a resin composition containing the above (A) propylene-ethylene random copolymer and the above (B') phase-soluble elastomer, and not containing the above (C) incompatible elastomer. In this case, in the innermost layer of the sealant layer, the occurrence of cracks during cold forming is further suppressed, and the insulation after molding can be further improved.

In the exterior material for a storage device, the metal foil layer and the sealant layer may be passed through the adhesive resin layer, and the adhesive resin layer may include an adhesive resin composition and an irregularly structured polypropylene. And/or a propylene-alpha olefin copolymer. In this case, in the adhesive resin layer, the occurrence of cracks due to stress during cold forming is more suppressed, and the insulation after molding can be further improved.

In the above-described exterior material for a storage device, the metal foil layer and the sealant layer may be passed through the second adhesive layer, and the second adhesive layer may include an acid-modified polyolefin resin; a polyfunctional isocyanate compound, a glycidyl compound, a compound having a carboxyl group, and the like At least one compound of the group of oxazoline group compounds. In this case, the adhesion between the second adhesive layer and the sealant layer is improved, and the interlayer peeling due to stress during cold forming and the occurrence of cracks due to the stress are suppressed, and it is possible to prevent the formation after the molding. Reduced insulation.

In the exterior material for an electrical storage device, the anticorrosive treatment layer may contain cerium oxide, 1 to 100 parts by mass of phosphoric acid or phosphate, and a cationic polymer with respect to 100 parts by mass of the cerium oxide. In this case, the adhesion between the metal layer, the adhesive resin layer or the second adhesive layer is improved, and the interlayer peeling due to stress during cold forming and the like The occurrence of cracks is suppressed, and the decrease in insulation after molding can be prevented.

In the exterior material for an electrical storage device, the corrosion-resistant treatment layer may be formed by subjecting the metal foil layer to a chemical conversion treatment, and may include a cationic polymer. In this case, the adhesion between the metal layer and the adhesive resin layer or the second adhesive layer is improved, and the interlayer peeling due to stress during cold forming and the occurrence of cracks due to the stress are suppressed. It is possible to prevent a decrease in insulation after molding.

According to the first aspect of the present invention, it is possible to provide an exterior material for a power storage device which can improve the sealing property of the electrolyte containing the degassing heat seal strength while suppressing the occurrence of the excessively sealed portion and the occurrence of molding whitening. .

Further, according to the second aspect of the present invention, it is possible to provide an exterior material for a power storage device which is excellent in insulation properties after molding and sealing properties relating to an electrolytic solution including degassing heat seal strength.

10, 20, 30‧‧‧ Exterior materials for power storage devices

11‧‧‧Substrate layer

12‧‧‧First adhesive layer

13‧‧‧metal foil layer

14‧‧‧Anti-corrosion treatment layer

15‧‧‧Adhesive resin layer

16‧‧‧Sealant layer

16a‧‧‧First sealant layer

16b‧‧‧Second sealant layer

17‧‧‧Secondary adhesive layer

40‧‧‧ sample

41‧‧‧Deep extension

42‧‧‧1

43‧‧‧Seal sealant

44‧‧‧Upper side

45‧‧‧sideside

46‧‧‧ exposed part of the metal foil layer

47‧‧‧The lower part

48a, 48b‧‧‧ electrodes

S1‧‧‧ Sealing Department

S2‧‧‧ Degassing seal

Fig. 1 is a schematic cross-sectional view showing an exterior material for a power storage device according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing an exterior material for a power storage device according to an embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view showing an exterior material for a power storage device according to an embodiment of the present invention.

[Fig. 4] is an illustration showing a method of producing a sample in an embodiment. intention.

Fig. 5 is a schematic view showing a method of producing an evaluation sample in the embodiment.

Fig. 6 is a schematic view showing a method of producing an evaluation sample in the embodiment.

[Formation of the Invention]

Hereinafter, an appropriate embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and the repeated description is omitted. Also, the dimensional ratio of the drawings is not limited by the ratios shown.

[External materials for power storage devices]

Fig. 1 is a cross-sectional view showing an embodiment of an exterior material for a storage battery device according to the first to second aspects of the invention. As shown in Fig. 1, the outer casing (the exterior material for an electrical storage device) 10 of the present embodiment is a laminated body in which a base material layer 11 is formed on one surface of the base material layer 11 in this order. The first adhesive layer 12, the metal foil layer 13 formed on the surface opposite to the base material layer 11 of the first adhesive layer 12, is formed opposite to the first adhesive layer 12 of the metal foil layer 13. The anti-corrosion treatment layer 14 on the surface, the adhesive resin layer 15 formed on the surface opposite to the metal foil layer 13 of the anti-corrosion treatment layer 14, and the anti-corrosion treatment formed on the adhesive resin layer 15 Layer 14 is the sealant layer 16 on the opposite side. The exterior material 10 is the outermost layer of the base material layer 11, and the sealant layer 16 is the innermost layer. In other words, the exterior material 10 is directed to the outer side of the power storage device, and the sealant layer 16 is used toward the inner side of the power storage device. Following, for Each layer will be described.

<Substrate layer 11>

The base material layer 11 is preferably provided with an insulating resin layer for the purpose of imparting heat resistance during the sealing step in the production of the electrical storage device and pinhole countermeasures which may occur during processing or distribution. For such a resin layer, for example, a stretched or unstretched film such as a polyester film, a polyamide film or a polypropylene film can be used as a single layer or a multilayer film in which two or more layers are laminated. More specifically, it is possible to use a co-extruded multilayered laminate obtained by coextruding a polyethylene terephthalate (PET) film and a nylon (Ny) film using an adhesive resin. Stretch the film.

The thickness of the base material layer 11 is preferably 6 to 40 μm, more preferably 10 to 25 μm. When the thickness of the base material layer 11 is 6 μm or more, the pinhole resistance and the insulation property of the exterior material 10 for an electrical storage device tend to be improved. On the other hand, the thickness of the base material layer 11 is 40 μm or less, and the deep drawing moldability of the exterior material 10 for an electrical storage device tends to be improved.

<First adhesive layer 12>

The first adhesive layer 12 is a layer in which the base material layer 11 and the metal foil layer 13 are bonded. Specific examples of the material constituting the first adhesive layer 12 include a difunctional or higher isocyanate compound to a polyester polyol, a polyether polyol, an acrylic polyol, and a carbonate polyol. A polyurethane resin or the like which is a main component such as an alcohol.

As the polyester polyol, an aliphatic or isophthalic acid such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or tridecanedioic acid can be used. Terephthalic acid, naphthalene dicarboxylic acid, etc. More than one of the scented dibasic acids; with ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methyl pentanediol, hexanediol, heptanediol, octanediol, decanediol, hydrazine An aliphatic type such as a diol or a dodecanediol, an alicyclic system such as cyclohexanediol or hydrogenated benzenedimethanol, or an aromatic diol such as benzenedimethanol is obtained.

Further, as the polyester polyol, for the hydroxyl group at both ends of the polyester polyol obtained by using the above dibasic acid and diol, for example, 2,4- or 2,6-diisocyanic acid is used. Toluene ester, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine lysine Diisocyante), 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methyl cyclohexane diisocyante, Isophorone diisocyanate, 4,4'-dicyclohexyl methane diisocyanate, isopropylidene dicyclohexyl-4, a polyester obtained by chain-extending a monomer of a selected isocyanate compound, or an adduct, a biuret or a trimeric isocyanate selected from the group consisting of at least one isocyanate compound, such as 4'-diisocyante) A urethane polyol or the like.

The polyether polyol can be an ether polyol such as polyethylene glycol or polypropylene glycol or a polyether urethane polyol obtained by reacting the above isocyanate compound as a chain length extender.

As the acrylic polyol, an acrylic resin obtained by polymerization using the above acrylic monomer can be used.

In the case of a carbonate polyol, a carbonate compound can be obtained by reacting with a diol. As the carbonate compound, dimethyl carbonate, diphenyl carbonate, ethylene carbonate or the like can be used. On the other hand, as the diol, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, methyl pentanediol, hexanediol, heptanediol, octanediol, decanediol, or the like can be used. An aliphatic diol such as decanediol or dodecanediol; an alicyclic diol such as cyclohexanediol or hydrogenated benzenedimethanol; or an aromatic diol such as benzenedimethanol. In the carbonate polyol, a carbonate polyol obtained by using one or a mixture of two or more kinds of the above-described carbonate compounds and one or a mixture of two or more of the above diols, or The isocyanate compound is subjected to a chain-stretched polycarbonate urethane polyol.

The above various polyols can be used singly or in combination of two or more depending on the function or performance required for the exterior material. Further, it is also possible to use a polyurethane-based adhesive by using the above-mentioned isocyanate-based compound as a curing agent for the main component.

Further, for the purpose of promoting the adhesion, a carbodiimide compound may be blended with the above-mentioned polyurethane resin, An oxazoline compound, an epoxy compound, a phosphorus compound, a decane coupling agent, or the like.

As the carbodiimide compound, for example, N,N'-di-o-tolylcarbyl carbodiimide, N,N'-diphenylcarbodiimide, N,N'- Bis-2,6-dimethylphenylcarbodiimide, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, N,N'-dioctylfluorene N-triyl-N'-cyclohexyl carbodiimide, N,N'-di-2,2-di (tertiary D-butyl) Phenylcarbodiimide Amine, N-triyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N' -di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-dicyclohexylcarbodiimide, N,N'-pair Tolylmethyl carbodiimide and the like.

on For the oxazoline compound, for example, 2- Oxazoline, 2-methyl-2- Oxazoline, 2-phenyl-2- Oxazoline, 2,5-dimethyl-2- Oxazoline, 2,4-diphenyl-2- Oxazoline Oxazoline compound; 2,2'-(1,3-phenylene)-bis(2- Oxazoline), 2,2'-(1,2-extended ethyl)-bis(2- Oxazoline), 2,2'-(1,4-butylene)-bis(2- Oxazoline), 2,2'-(1,4-phenylene)-bis(2- Oxazoline) Oxazoline compound.

The epoxy compound may, for example, be a di-epoxypropyl ether of an aliphatic diol such as 1,6-hexanediol, neopentyl glycol or a polyalkylene glycol, sorbitol or sorbitol. Polyepoxypropyl ether of an aliphatic polyol such as anhydride, polyglycerol, neopentyl alcohol, diglycerin, glycerin or trimethylolpropane, polyepoxypropyl group of an alicyclic polyol such as cyclohexane dimethanol Di-epoxypropyl ester of an aliphatic or aromatic polycarboxylic acid such as ether, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, trimellitic acid, adipic acid or sebacic acid Or polyepoxypropyl ester, resorcinol, bis-(p-hydroxyphenyl)methane, 2,2-bis-(p-hydroxyphenyl)propane, cis-(p-hydroxyphenyl)methane, 1,1 , di-epoxypropyl ether or polyepoxypropyl ether of polyphenols such as 2,2-indole (p-hydroxyphenyl)ethane, N,N'-diepoxypropylaniline, N,N,N- N-epoxypropyl derivative of diepoxypropyl toluidine, N,N,N',N'-tetraepoxypropyl-bis-(p-aminophenyl)methane, aminophenol Triepoxypropyl derivative, triepoxypropyl ginseng (2-hydroxyethyl) trimeric isocyanate Ester, triepoxypropyl trimer isocyanate, o-cresol type epoxide, phenol novolac type epoxide.

As the phosphorus compound, for example, ginseng (2,4-di(tri-butyl)phenyl)phosphite, ruthenium (2,4-di(tri-butyl)phenyl) 4,4' - bisphenylphosphonate, bis(2,4-di(tributyl)phenyl)neopentanol-di-phosphite, bis(2,6-di(tri-butyl) -4-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis(4,6-di(tri-butyl)phenyl)octyl phosphite, 4, 4'-butylidene-bis(3-methyl-6-tris-butylphenyl-di-tridecyl) phosphite, 1,1,3-glycol (2-methyl-4-di Tridecyl phosphite-5-tertiary butyl-phenyl)butane, ginseng (mixed mono- and di-nonylphenyl) phosphite, hexamethylenephenyl phosphite, 4 , 4'-isopropylidene bis(phenyl-dialkyl phosphite), and the like.

As the decane coupling agent, for example, vinyl triethoxy decane, vinyl ginseng ( β -methoxyethoxy) decane, γ -methyl propylene methoxy propyl trimethoxy decane, ethylene can be used. Triethyl decyloxydecane, γ -glycidoxypropyltrimethoxydecane, γ -glycidoxypropyltriethoxydecane, β- (3,4-epoxycyclohexyl)B Trimethoxy decane, γ -chloropropyl methoxy decane, vinyl trichloro decane, γ -mercaptopropyl trimethoxy decane, γ -aminopropyl triethoxy decane, N- β (amino group ethyl) - γ - aminopropyl trimethoxy Silane Silane coupling agents other.

Further, depending on the properties required for the adhesive, various other additives and stabilizers may be blended in the above-mentioned polyurethane resin.

The thickness of the first adhesive layer 12 is not particularly limited, and is preferably from 1 to 10 μm, more preferably from 3 to 7 μm, from the viewpoint of obtaining desired adhesive strength, followability, and processability.

<Metal foil layer 13>

The metal foil layer 13 has water vapor barrier properties for preventing moisture from penetrating into the interior of the electricity storage device. Further, in order to perform deep drawing, the metal foil layer 13 has ductility. As the metal foil layer 13, various metal foils such as aluminum and stainless steel can be used, and aluminum foil is preferable in terms of mass (specific gravity), moisture resistance, workability, and cost.

As the aluminum foil, a general soft aluminum foil can be used for the purpose of imparting further pinhole resistance and ductility during molding, and an aluminum foil containing iron is preferably used. In 100% by mass of the aluminum foil, the content of iron in the aluminum foil is preferably from 0.1 to 9.0% by mass, more preferably from 0.5 to 2.0% by mass. When the content of iron is 0.1% by mass or more, the exterior material 10 having more excellent pinhole resistance and ductility can be obtained. On the other hand, since the content of iron is 9.0% by mass or less, the exterior material 10 having more excellent flexibility can be obtained.

In addition, the aluminum foil is preferably a soft aluminum foil which has been subjected to annealing treatment (for example, 8021 material and 8079 material which are referred to by JIS standards) from the viewpoint of imparting desired ductility during molding. Aluminum foil).

Although the thickness of the metal foil layer 13 is not particularly limited, it is preferably 9 to 200 μm, more preferably 15 to 100 μm, in view of barrier properties, pinhole resistance, and workability.

When an aluminum foil is used for the metal foil layer 13, an untreated aluminum foil can be used for the aluminum foil, and an aluminum foil which has been subjected to degreasing treatment is preferably used at the point of imparting electrolyte resistance. In the case of degreasing treatment, if it is roughly divided, it can be wet and dry.

Examples of the wet type include acid degreasing and alkali degreasing. Just For the acid to be used for the degreasing, for example, an inorganic acid such as sulfuric acid, nitric acid, hydrochloric acid or hydrofluoric acid may be used. These inorganic acids may be used alone or in combination of two or more. Moreover, from the viewpoint of improving the etching effect of the aluminum foil, various metal salts which are synthesized as a supply source of Fe ions or Ce ions may be required as needed. The base to be used for alkali degreasing includes, for example, a strong etching type such as sodium hydroxide. Further, those in which a weak base or a surfactant is blended may also be used. These degreasing are carried out by a dipping method or a spraying method.

In the dry type, a method of performing degreasing treatment in the step of annealing aluminum. Further, in addition to the degreasing treatment, flame treatment, corona treatment, or the like may be performed. Further, a degreasing treatment such as oxidative decomposition/removal of a contaminant by irradiation with active oxygen generated by ultraviolet rays of a specific wavelength may be employed.

Further, when the aluminum foil is subjected to degreasing treatment, only one side of the aluminum foil may be subjected to degreasing treatment, or both sides may be subjected to degreasing treatment.

<Anti-corrosion treatment layer 14>

The anticorrosive treatment layer 14 is a layer provided to prevent corrosion of the metal foil layer 13 due to hydrofluoric acid generated by the reaction of the electrolytic solution or the electrolyte solution and moisture. The anti-corrosion treatment layer 14 can be formed, for example, by a degreasing treatment, a hot water deterioration treatment, an anodizing treatment, a chemical conversion treatment, or a combination of such treatments.

In the case of the degreasing treatment, acid degreasing or alkali degreasing may be mentioned. The acid degreasing may be a mineral acid such as sulfuric acid, nitric acid, hydrochloric acid or hydrofluoric acid alone or a method of using such a mixed liquid. Further, in the case of acid degreasing, an acid degreasing agent obtained by dissolving a fluorine-containing compound such as monosodium ammonium difluoride or the like is used, in particular, a metal foil. In the case where the aluminum foil is used for the layer 13, not only the degreasing effect of aluminum but also the fluoride of the passive aluminum can be formed, and it is effective at the point of hydrogen fluoride resistance. As the alkali degreasing, a method such as sodium hydroxide can be used.

The hot water metamorphic treatment may, for example, be a boehmite treatment in which an aluminum foil is immersed in boiling water to which triethanolamine is added.

For the anodizing treatment, for example, an alumite treatment can be mentioned.

The chemical conversion treatment may be an immersion type or a coating type. The immersion type chemical conversion treatment may, for example, be chromate treatment, zirconium treatment, titanium treatment, vanadium treatment, molybdenum treatment, calcium phosphate treatment, strontium hydroxide treatment, hydrazine treatment, hydrazine treatment, or These various mixed phases constitute various chemical conversion treatments. On the other hand, as for the coating type chemical conversion treatment, a method of applying a coating agent having corrosion resistance to the metal foil layer 13 can be mentioned.

In the anti-corrosion treatment, when at least a part of the anti-corrosion treatment layer is formed by any one of hot water modification treatment, anodizing treatment, and chemical conversion treatment, it is preferred to carry out the degreasing treatment beforehand. Further, when the metal foil which has been subjected to the degreasing treatment is used as the metal foil layer 13, it is not necessary to perform the degreasing treatment again in the formation of the anticorrosive treatment layer 14.

The coating agent used in the coating type chemical conversion treatment preferably contains trivalent chromium. Further, the coating agent may include at least one polymer selected from the group consisting of a cationic polymer and an anionic polymer described later.

Moreover, among the above processes, in particular, hot water deterioration treatment, The anodizing treatment is performed by dissolving the surface of the aluminum foil through a treatment agent to form an aluminum compound (aluminous mineral, aluminum-resistant aluminum) excellent in corrosion resistance. Therefore, since it forms a co-continuous structure from the metal foil layer 13 using the aluminum foil to the anti-corrosion treatment layer 14, it is included in the definition of a chemical conversion process. Further, the corrosion-resistant treatment layer 14 can be formed only by a pure coating method not included in the definition of the general chemical conversion treatment as will be described later. In this method, for example, a sol of a rare earth element oxide such as cerium oxide having an average particle diameter of 100 nm or less can be used as an anticorrosive effect (inhibitor effect) having aluminum, and also in terms of environmental considerations. A method of suitable materials. By using this method, it is also possible to impart an anticorrosive effect to a metal foil such as an aluminum foil by a general coating method.

The sol of the rare earth element oxide is, for example, a sol having various solvents such as an aqueous system, an alcohol system, a hydrocarbon system, a ketone system, an ester system, and an ether system. Among them, a water-based sol is preferred.

In the sol of the rare earth element oxide, in order to stabilize the dispersion, an organic acid such as nitric acid, hydrochloric acid or phosphoric acid or a salt thereof, or an organic acid such as acetic acid, malic acid, ascorbic acid or lactic acid can be used as the dispersion. stabilizer. Among these dispersion stabilizers, in particular, phosphoric acid, in the exterior material 10, (1) dispersion stabilization of the sol; (2) improvement in adhesion to the metal foil layer 13 by utilizing the aluminum chelate ability of phosphoric acid (3) imparting the tolerance of the electrolyte to the aluminum ions eluted by the influence of hydrofluoric acid (forming a passive state); (4) causing dehydration condensation of phosphoric acid even at low temperatures The improvement of the cohesive force of the anti-corrosion treatment layer 14 (oxide layer) is expected.

As the above phosphoric acid or a salt thereof, there may be mentioned orthophosphoric acid and coke. Phosphoric acid, metaphosphoric acid, or such alkali metal or ammonium salts. Among them, the functional expression in the exterior material 10 is preferably a condensed phosphoric acid such as a trimetaphosphoric acid, a tetrametaphosphoric acid, a hexametaphosphoric acid or a hypermetaphosphoric acid, or such an alkali metal salt or an ammonium salt. In addition, in consideration of the dry film forming property (drying ability, heat) when the anticorrosive treatment layer 14 composed of the rare earth element oxide is formed by using the sol of the rare earth element oxide described above, the low temperature is In view of excellent dehydration and condensability at a low temperature, a sodium salt is more preferable. In the case of phosphate, a water-soluble salt is preferred.

The blending of the phosphoric acid (or a salt thereof) with respect to the rare earth element oxide is preferably from 1 to 100 parts by mass based on 100 parts by mass of the rare earth element oxide. When the blending ratio is 1 part by mass or more based on 100 parts by mass of the rare earth element oxide, the rare earth element oxide sol becomes more stable, and the function of the exterior material 10 becomes more favorable. The blend ratio is more preferably 5 parts by mass or more based on 100 parts by mass of the rare earth element oxide. In addition, when the blending ratio is 100 parts by mass or less based on 100 parts by mass of the rare earth element oxide, the function of the rare earth element oxide sol is improved, and the performance of preventing electrolyte corrosion is excellent. The blending ratio is more preferably 50 parts by mass or less, still more preferably 20 parts by mass or less, based on 100 parts by mass of the rare earth element oxide.

The anticorrosive treatment layer 14 formed of the rare earth element oxide sol has a cohesive force of the layer itself due to the step of drying and solidifying due to the assembly of the inorganic particles. Therefore, in order to reinforce the cohesive force, the anticorrosive treatment layer 14 in this case is preferably compounded by the following anionic polymer or a cationic polymer.

In the case of an anionic polymer, a polycondensation having a carboxyl group is exemplified. The compound may, for example, be a poly(meth)acrylic acid (or a salt thereof) or a copolymer obtained by copolymerizing poly(meth)acrylic acid as a main component. The copolymerization component of the copolymer may, for example, be an alkyl (meth)acrylate monomer (in the case of an alkyl group: methyl, ethyl, n-propyl, isopropyl, n-butyl) , isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl, etc.); (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl ( Methyl) acrylamide (for alkyl groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl, etc.) .), N-alkoxy (meth) acrylamide, N, N-dialkoxy (meth) acrylamide (in the case of alkoxy groups: methoxy, ethoxy, butoxy Base, isobutoxy, etc.), N-hydroxymethyl (meth) acrylamide, N-phenyl (meth) acrylamide, etc., containing a guanamine group; 2-hydroxyethyl (A a hydroxyl group-containing monomer such as acrylate or 2-hydroxypropyl (meth) acrylate; a monopropyl group containing a glycidyl group such as a glycidyl (meth) acrylate or an allyl epoxypropyl ether a monomer containing decane such as (meth)acryloxypropyltrimethoxydecane or (meth)acryloxypropyltriethoxydecane ; (Meth) Bing Xixi propyl isocyanate monomers containing an isocyanate group.

These anionic polymerizations have a function of improving the stability of the anticorrosive treatment layer 14 (oxide layer) obtained by using a rare earth element oxide sol. This is achieved by the effect of protecting the hard and brittle oxide layer by the acrylic resin component and the ionic contamination (especially sodium) which is derived from the phosphate contained in the rare earth element oxide sol. Ion) (cation trap) effect. That is, obtained by using a rare earth element oxide sol In the anti-corrosion treatment layer 14, in particular, if an alkali metal ion such as sodium or an alkaline earth metal ion is contained, the anti-corrosion treatment layer 14 is easily deteriorated from the point where the ion is contained. Therefore, the sodium ion or the like contained in the rare earth element oxide sol is fixed by the anionic polymer, whereby the resistance of the anticorrosive treatment layer 14 is improved.

The anticorrosive treatment layer 14 in which the anionic polymer and the rare earth element oxide sol are combined has the same anticorrosive performance as the anticorrosive treatment layer 14 formed by subjecting the aluminum foil to chromate treatment. The anionic polymer is preferably a crosslinked structure of a water-soluble polyanionic polymer in nature. Examples of the crosslinking agent used for the formation of the structure include an isocyanate group, a glycidyl group, and a carboxyl group. An oxazoline group compound.

As the compound having an isocyanate group, for example, toluene diisocyanate, benzoyl diisocyanate or a hydride thereof, hexamethylene diisocyanate or 4,4' diphenylmethane can be mentioned. Isocyanate or a hydrogenated product thereof, a diisocyanate such as isophorone diisocyanate; or an adduct obtained by reacting the isocyanate with a polyhydric alcohol such as trimethylolpropane, and reacting the isocyanate with water; a obtained polyisocyanate such as a biuret or a trimer isocyanate; or a polyisocyanate obtained by blocking the polyisocyanate with an alcohol, an indoleamine, an anthracene or the like Block polyisocyanate and the like.

Examples of the compound having a glycidyl group include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, and 1,4-. Ethylene oxides such as butanediol, 1,6-hexanediol, neopentyl glycol, etc., which react with epichlorohydrin An epoxy compound obtained by reacting a polyhydric alcohol such as glycerin, polyglycerol, trimethylolpropane, neopentyl alcohol or sorbitol with epichlorohydrin; and phthalic acid, terephthalic acid, oxalic acid An epoxy compound obtained by reacting a dicarboxylic acid such as adipic acid with epichlorohydrin.

Examples of the compound having a carboxyl group include various aliphatic or aromatic dicarboxylic acids. Further, an alkali (earth) metal salt of poly(meth)acrylic acid or poly(meth)acrylic acid can also be used.

Have An oxazoline group compound, for example, when used, has two or more a low molecular compound of an oxazoline unit, or an isopropenyl group In the case of a polymerizable monomer of oxazoline, an acrylic monomer such as (meth)acrylic acid, alkyl (meth)acrylate or hydroxyalkyl (meth)acrylate may be copolymerized.

Further, in the anionic polymer, the amine may be selectively reacted with a functional group like a decane coupling agent, and the crosslinking point may become a decane bond. In this case, use: γ -glycidoxypropyltrimethoxydecane, γ -glycidoxypropyltriethoxydecane, β- (3,4-epoxycyclohexyl)ethyl Trimethoxy decane, γ-chloropropyl methoxy decane, vinyl trichloro decane, γ -mercaptopropyl trimethoxy decane, γ -aminopropyl triethoxy decane, N- β (amino group B Base) - γ -aminopropyltrimethoxydecane, γ -isocyanatepropyltriethoxydecane, and the like. Among them, epoxy decane, amino decane, and isocyanate decane are preferable in particular in consideration of reactivity with an anionic polymer or a copolymer thereof.

The ratio of the crosslinking agent to the anionic polymer is preferably from 1 to 50 parts by mass, more preferably from 10 to 20 parts by mass, per 100 parts by mass of the anionic polymer. 100 parts by mass relative to the anionic polymer When the ratio of the crosslinking agent is 1 part by mass or more, it is easy to sufficiently form a crosslinked structure. When the ratio of the crosslinking agent is 50 parts by mass or less based on 100 parts by mass of the anionic polymer, the pot life of the coating liquid is increased.

The method of crosslinking the anionic polymer is not limited to the above-mentioned crosslinking agent, and a method of forming ionic crosslinking using titanium or a zirconium compound may be used.

The cationic polymer may, for example, be a polymer having an amine, and may be a polyethyleneimine, an ionic polymer complex composed of a polymer of polyethyleneimine and a carboxylic acid, and grafting a primary amine. A cationic polymer such as an acrylic resin, a polyallylamine or the like, or an aminophenol in a primary amine grafting of an acrylic main skeleton.

The cationic polymer is preferably used in combination with a crosslinking agent having a functional group capable of reacting with an amine/imine such as a carboxyl group or a epoxypropyl group. As the crosslinking agent to be used in combination with the cationic polymer, a polymer having a carboxylic acid which forms an ionic polymer complex with polyethyleneimine may be used, and for example, polyacrylic acid or an ionic salt thereof may be used. A carboxylic acid (salt) or a polysaccharide having a carboxyl group such as a copolymer in which a comonomer is introduced, carboxymethylcellulose or an ionic salt thereof. Examples of the polyallylamine include a homopolymer or a copolymer such as allylamine, allylamine sulfonamide sulfate, diallylamine or dimethylallylamine. The amines may be free amines or may be stabilised by acetic acid or hydrochloric acid. Further, as the copolymer component, maleic acid, sulfur dioxide or the like can also be used. Further, a type in which thermal crosslinking property is imparted by methoxylation of the primary amine moiety may be used, and an aminophenol may also be used. Particularly preferred is allylamine or a derivative thereof.

In the present embodiment, the cationic polymer is also described. It is a constituent element constituting the anti-corrosion treatment layer 14. The reason for this is that the cationic polymer itself is also intensively examined by using various compounds in order to provide the electrolyte resistance and the hydrofluoric acid resistance required for the external storage material for the electrical storage device. It is a compound which can provide electrolyte resistance and hydrofluoric acid resistance. The reason for this is presumed to be that the damage of the aluminum foil is suppressed by the use of the cationic group to capture the fluoride ion (anion trap).

Cationic polymers are a better material at the point of improving adhesion. Further, it is more preferable that the cationic polymer is water-soluble similarly to the above anionic polymer, and the crosslinked structure is formed to impart water resistance. The crosslinking agent which forms a crosslinked structure in a cationic polymer can be used as a crosslinking agent demonstrated by the item of an anionic polymer. When a rare earth element oxide sol is used as the anticorrosive treatment layer 14, a cationic polymer may be used instead of using the above anionic polymer as a protective layer.

The anti-corrosion treatment layer caused by the chemical conversion treatment represented by the chromate treatment, in order to form an inclined structure with the aluminum foil, in particular, chemical conversion in which hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid or the salts are blended is used. The treatment agent is applied to the aluminum foil, and then a chromium or non-chromium compound is applied to form the chemical conversion treatment layer on the aluminum foil. However, since the above chemical conversion treatment uses an acid in the chemical conversion treatment agent, it is accompanied by deterioration of the work environment and corrosion of the coating device. On the other hand, the coating type anticorrosive treatment layer 14 is different from the chemical conversion treatment typified by the chromate treatment, and it is not necessary to form the inclined structure of the metal foil layer 13 using the aluminum foil. Therefore, the properties of the coating agent are not affected by acidity, alkalinity, Neutral and other restrictions can achieve a good working environment. In addition, the chromate treatment using a chromium compound is preferably a coating type anticorrosive treatment layer 14 from the viewpoint of environmentally desirable alternatives.

Based on the above, examples of the combination of the coating type anticorrosive treatment include (1) only a rare earth element oxide sol, (2) an anionic polymer, and (3) a cationic polymer only. (4) rare earth element oxide sol + anionic polymer (layered composite), (5) rare earth element oxide sol + cationic polymer (layered composite), (6) (rare earth element oxide sol + anionic polymer: laminated composite) / cationic polymer (multilayered), (7) (rare earth element oxide sol + cationic polymer: laminated composite) / anionic polymer (multilayered), etc. . Among them, preferred are (1) and (4) to (7), and particularly preferred are (4) to (7). However, the present embodiment is not limited to the above combination. For example, in the case of selecting an anticorrosive treatment, the cationic polymer is followed by a modified polyolefin resin as exemplified in the description of the sealant adhesive layer (the adhesive resin layer or the second adhesive layer) described later. Goodness is also a very good material, so in the case where the sealant is layered with a modified polyolefin resin, the cationic polymer is placed on the surface of the sealant layer ( For example, designs such as structures (5) and (6) are possible.

Further, the anticorrosive treatment layer 14 is not limited to the above layer. For example, it can be formed by using a treatment agent such as a coating type chromate of a known technique in which a resin binder (such as an aminophenol) is blended with a phosphoric acid and a chromium compound. When this treatment agent is used, it is possible to form a layer having both an anticorrosive function and an adhesive property. Also, although the stability of the coating liquid needs to be considered, A coating agent obtained by liquefying a rare earth element oxide sol with a polycationic polymer or a polyanionic polymer in advance can be used to form a layer having both an anticorrosive function and an adhesive property.

Corrosion prevention treatment layer 14 mass per unit area, regardless of who is a multilayer structure, any of a single layer structure is preferably 0.005 ~ 0.200g / m ^2, more preferably 0.010 ~ 0.100g / m ^2. When the mass per unit area is 0.005 g/m ² or more, the metal foil layer 13 is easily provided with an anticorrosive function. Further, even if the mass per unit area described above exceeds 0.200 g/m ² , the anticorrosive function does not change much. On the other hand, when a rare earth element oxide sol is used, if the coating film is thick, curing due to heat during drying may be insufficient, and there may be a decrease in cohesive force. Further, the thickness of the anti-corrosion treatment layer 14 can be converted from the specific gravity.

<Adhesive resin layer 15>

The adhesive resin layer 15 has a schematic configuration including an adhesive resin composition which is a main component and an additive component which is contained as necessary. The resin composition is not particularly limited, and preferably contains a modified polyolefin resin (a) component and a macroscopic phase-separated thermoplastic elastomer (b) component. Further, the additive component preferably comprises an irregularly structured polypropylene and/or propylene- alpha olefin copolymer. Among them, the additive component more preferably comprises an irregularly structured polypropylene and/or an irregularly structured propylene- alpha olefin copolymer (c). Hereinafter, each component will be described.

(modified polyolefin resin (a))

The modified polyolefin resin (a) is preferably an unsaturated carboxylic acid derivative component derived from an unsaturated carboxylic acid, an anhydride of an unsaturated carboxylic acid, or an ester of an unsaturated carboxylic acid, which is carried out in a polyolefin resin. A graft modified resin.

As the polyolefin resin, for example, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene- α olefin copolymer, homo, block, or random polypropylene, propylene- α olefin A polyolefin resin such as a copolymer is preferably a polypropylene resin from the viewpoint of adhesion to the sealant layer 16 .

The compound to be used for the graft modification of the polyolefin resin may be an unsaturated one derived from an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or an unsaturated carboxylic acid ester. A carboxylic acid derivative component.

Specifically, examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and bicyclo [2, 2, 1] Hept-2-ene-5,6-dicarboxylic acid and the like.

Examples of the acid anhydride of the unsaturated carboxylic acid include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2,2,1]hept-2-ene-5,6. An acid anhydride or the like of an unsaturated carboxylic acid such as a dicarboxylic acid anhydride.

Examples of the ester of the unsaturated carboxylic acid include methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, and monomethyl maleate. Diethyl fumarate, dimethyl iconate, diethyl citraconic acid, dimethyl tetrahydrophthalic anhydride, bicyclo[2,2,1]hept-2-ene-5,6-di An ester of an unsaturated carboxylic acid such as dimethyl carboxylate.

The modified polyolefin resin (a) can be produced by using the above unsaturated carboxylic acid derivative component in the presence of a radical initiator in an amount of 0.2 to 100 with respect to 100 parts by mass of the polyolefin resin to be a matrix. The mass parts were subjected to graft polymerization (graft modification). The reaction temperature for graft modification is preferably 50 to 250 ° C, more preferably 60 to 200 ° C. Further, the reaction time is appropriately set according to the production method. For example, in the case of melt graft polymerization by a twin-screw extruder, the residence time of the extruder is specifically preferably 2 to 30 minutes, more preferably Good for 5~10 minutes. Further, the graft modification can be carried out under any conditions of normal pressure and pressure.

The radical initiators used in the graft modification include alkyl peroxides, aryl peroxides, mercapto peroxides, ketone peroxides, peroxyketals, peroxycarbonates, Organic peroxides such as peroxyesters and hydrogen peroxide.

These organic peroxides can be appropriately selected and used depending on the conditions of the above reaction temperature and reaction time. For example, in the case of melt graft polymerization by a twin-screw extruder, an alkyl peroxide, a peroxyketal, a peroxy ester, and more preferably a di(tertiary butyl) group is preferred. Oxide, 2,5-dimethyl-2,5-di(tributyl)peroxy-hexyne-3, dicumyl peroxide, and the like.

The modified polyolefin resin (a) is preferably a polyolefin resin modified with maleic anhydride, for example, "Admer" manufactured by Mitsui Chemicals Co., Ltd., "Modic" manufactured by Mitsubishi Chemical Corporation, etc. of. The modified polyolefin resin (a) component is excellent in reactivity with various metals and polymers having various functional groups, and it is possible to impart adhesion to the adhesive resin layer 15 by utilizing the reactivity. Improve electrolyte resistance.

(Macro phase separation thermoplastic elastomer (b))

The macroscopic phase-separated thermoplastic elastomer (b) has a dispersed phase size of more than 200 nm and 50 μm or less with respect to the modified polyolefin resin (a). To form a macroscopic phase separation constructor.

The residual resin composition contains the macroscopic phase-separated thermoplastic elastomer (b) component, and the residual stress generated when the modified polyolefin resin (a) component which is the main component of the adhesive resin layer 15 is laminated It is released and can impart thermoelastic adhesion to the adhesive resin layer 15. Therefore, the adhesiveness of the adhesive resin layer 15 is further improved, and the exterior material 10 which is more excellent in electrolyte solution resistance can be obtained.

The macroscopic phase-separated thermoplastic elastomer (b) exists on the modified polyolefin resin (a) in the form of islands. However, if the dispersed phase size is 200 nm or less, it becomes difficult to impart an improvement in viscoelasticity. On the other hand, if the dispersed phase size exceeds 50 μm, the modified polyolefin resin (a) and the macroscopic phase-separated thermoplastic elastomer (b) are intrinsically incompatible, so the layer suitability (processability) is remarkably lowered, and The physical strength of the resin layer 15 is easily lowered. Based on the above, the dispersed phase size is preferably from 500 nm to 10 μm.

In the case of such a macroscopic phase-separated thermoplastic elastomer (b), for example, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1- A polyolefin-based thermoplastic elastomer obtained by copolymerizing pentene α -olefin with ethylene and/or propylene.

In addition, as for the macroscopic phase-separated thermoplastic elastomer (b) component, commercially available products such as "Tafmer" manufactured by Mitsui Chemicals Co., Ltd., "Zelas" manufactured by Mitsubishi Chemical Corporation, and "Catalloy" manufactured by MONTELL Co., Ltd. can be used. Wait for the right one.

In the adhesive resin layer 15, the macroscopic phase-separated thermoplastic elastomer (b) component in the adhesive resin composition is relative to the modified polyolefin tree The content of the component (a) is preferably from 1 to 40 parts by mass, more preferably from 5 to 30 parts by mass, per 100 parts by mass of the modified polyolefin resin (a) component. When the content of the macrophase-separated thermoplastic elastomer (b) component is less than 1 part by mass, the adhesion of the adhesive resin layer cannot be expected to be improved. On the other hand, the content of the macroscopic phase-separated thermoplastic elastomer (b) component is more than 40 parts by mass, and the modified polyolefin resin (a) component and the macroscopic phase-separated thermoplastic elastomer (b) component are inherently low in compatibility. For this reason, the workability is easily reduced significantly. Further, since the macroscopic phase-separated thermoplastic elastomer (b) component is not a resin exhibiting adhesion, the adhesion of the adhesive resin layer 15 to other layers such as the sealant layer 16 and the anti-corrosion treatment layer 14 is liable to lower.

(Irregularly constructed polypropylene and/or irregularly structured propylene- alpha olefin copolymer (c))

The resin layer 15 preferably contains an irregular structure of polypropylene and/or an propylene- α- olefin copolymer having an irregular structure (hereinafter, simply referred to as "component (c)") as an additive component. Here, the component (c) is a completely amorphous resin component.

The polypropylene having an irregular structure and/or the propylene- α- olefin copolymer having an irregular structure means that the side chains of at least one of propylene and α -olefin are arranged in an irregular structure. In other words, in terms of such a structure, the following four cases can be cited.

(1) The case where the alignment of the side chain of the propylene chain of polypropylene is an irregular structure.

(2) A case where the alignment of the side chain of the propylene chain in the propylene- α- olefin copolymer is an irregular structure.

(3) A case where the alignment of the side chain of the α -olefin chain in the propylene- α- olefin copolymer is an irregular structure.

(4) A case where the alignment of the side chain of the propylene/ α -olefin complex chain in the propylene- α- olefin copolymer is an irregular structure.

The irregular structure of the polypropylene or propylene- α- olefin copolymer according to the present embodiment can be confirmed, for example, by the following method. First, a homopolymer polypropylene is polymerized using a transition metal complex used in the polymerization of a polypropylene or a propylene- α- olefin copolymer according to the present embodiment. Next, when the intensity of each of the signals of mm, mr, and rr of the carbon of the methyl group attributed to propylene is represented by [mm], [mr], and [rr] by ¹³ C-NMR spectroscopy, the following can be obtained. F(1) as defined by the formula. When the value of F(1) obtained by the above formula is 40 or more and 60 or less, it can be determined that the homopolypropylene obtained by the above polymerization has an irregular structure. The value of F(1) is preferably 43 or more and 57 or less, and more preferably 45 or more and 55 or less. When the value of F(1) is within the above range, the occurrence of cracks due to stress during cold forming is more suppressed in the adhesive resin layer, and the insulation after molding can be further improved.

F(1)=100×[mr]/([mm]+[mr]+[rr])

In the following, the effect of adding the additive component (c) to the adhesive resin composition which becomes a main component in the adhesive resin layer 15 is demonstrated.

When the adhesive resin layer 15 is in a molten state, the component (c) is compatible with the modified polyolefin resin (a) component in the adhesive resin composition, but is discharged to the crystal at the time of crystallization accompanying cooling. Outside, it becomes phase separation. Thus, component (c) does not hinder the adhesion of the main component. The degree of crystallization of the modified polyolefin resin (a) component in the resin composition. In addition, since the component (c) is added to the adhesive resin layer 15, the concentration of the modified polyolefin resin (a) is diluted by the component (c), and the crystal growth is suppressed, whereby the matrix resin can be made. The crystallinity (spherulite size) of the subsequent component (i.e., the modified polyolefin resin (a) component) is decreased. Further, the component (c) discharged to the outside of the crystal is uniformly dispersed around the microspheres of the modified polyolefin resin (a) component.

Incidentally, it has been known that "whitening phenomenon" occurs when the exterior material is cold-formed. Here, the mechanism of the whitening phenomenon will be described by taking the adhesive resin layer 15 in which the modified polyolefin resin (a) is blended with the macro phase-separated thermoplastic elastomer (b) as an example.

(1) The modified polyolefin resin (a) in the adhesive resin layer 15 is crystallized by heat treatment at the time of thermal lamination.

(2) Since the modified polyolefin resin (a) and the macroscopic phase-separated thermoplastic elastomer (b) are incompatible, the crystallization behavior of (1) causes a skew at the interface between the two.

(3) Stress is applied during forming, and cracks occur at the interface between the two to form pore-cracking.

(4) Light scattering due to pore-cracking, whitening due to diffusion of optical light occurs.

In other words, in order to suppress the whitening phenomenon, it is known that "the olefin is not modified by the heat at the time of thermal lamination (that is, it is difficult to crystallize)" and "improving the modified polyolefin" Adhesion between the resin (a) and the macroscopic phase-separated thermoplastic elastomer (b).

On the other hand, by being the main member of the adhesive resin layer 15 The adhesive component-added component (c) of the component is used as an additive component, and since the crystal size (spherulite size) of the modified polyolefin resin (a) component can be reduced, a film property which is soft and tough can be obtained. . In addition, it is considered that since the component (c) is uniformly dispersed in the periphery of the modified polyolefin resin (a), the stress can be uniformly alleviated, and the occurrence of void-cracking can be suppressed, so that the stress accompanying the molding can be alleviated. The exterior material 10 "whitening phenomenon".

By adding the component (c) as the additive component to the adhesive resin composition which is the main component of the adhesive resin layer 15 as described above, the transparency of the adhesive resin layer 15 can be improved, and the whitening of the stress accompanying the molding can be alleviated. phenomenon. Thereby, the molding whitening is also improved, and the insulation (bending resistance) of the bending stress of the exterior material 10 is improved. In addition, since the degree of crystallization of the modified polyolefin resin component (a) in the adhesive resin layer 15 is maintained, flexibility can be imparted, and the lamination strength of the exterior material 10 can be suppressed when the electrolyte solution is swollen. reduce.

In addition, by adding the component (c) as an additive component to the adhesive resin composition which is a main component of the adhesive resin layer 15, the crystallization of the modified polyolefin resin component (a) in the adhesive resin layer 15 is maintained. In addition, it is possible to suppress the decrease in the lamination strength of the exterior material 10 when the electrolyte is swollen, and to prevent the occurrence of void-cracking due to stress during cold forming, thereby providing insulation after molding. More improvement.

The ratio of the component (c) in the adhesive resin layer 15 is preferably 2.5% by mass, and more preferably 5% by mass or more. Upper limit The value is preferably 60% by mass. When the ratio of the component (c) in the adhesive resin layer 15 is less than 2.5% by mass, the effect due to the addition of the component (c) may not be sufficiently obtained. On the other hand, if it exceeds 60% by mass (that is, if the ratio of the adhesive resin composition is less than 40% by mass), the adhesion of the adhesive resin layer 15 to other layers such as the sealant layer 16 and the corrosion-resistant treatment layer 14 There is a tendency to become easy to reduce.

(Isotactic Structure of Propylene- α- Olefin Copolymer (d))

In addition to the above component (c), the resin layer 15 preferably further contains an isotactic structure of a propylene- α- olefin copolymer (hereinafter simply referred to as "component (d)") as an additive component.

Here, in the adhesive resin component which is the main component of the adhesive resin layer 15, especially when the modified polyolefin resin (a) is a polypropylene-based adhesive resin, the component (d) acts as a compatible rubber component. And inhibiting the crystallization of the modified polyolefin resin (a).

In other words, by further adding the component (d) as an additive component to the adhesive resin component which is a main component of the adhesive resin layer 15, it is possible to impart flexibility to alleviate stress, and thus it is possible to suppress the electrolyte lamination strength. The reduction is achieved by improving the heat seal strength (especially the electrolyte resistance) and improving the degassing seal strength. Further, by combining the component (c) and the component (d) as an additive component, it is possible to further improve the whitening phenomenon and the bending insulation resistance.

In addition, by further adding the component (d) as an additive component to the adhesive resin component which is a main component of the adhesive resin layer 15, it is possible to impart flexibility for relieving stress, and it is possible to suppress stress generation accompanying cold forming. The porosity-cracking can improve the insulation after molding.

The ratio of the additive component (that is, the total amount of the component (c) to the component (d)) in the subsequent resin layer 15 is preferably from 5 to 60% by mass. Here, the proportion of the additive component in the adhesive resin layer 15 is less than 5% by mass (that is, the ratio of the adhesive resin composition is more than 95% by mass), and the additive may not be sufficiently obtained as described above. The tendency to cause the effect. On the other hand, if it exceeds 60% by mass (that is, the ratio of the adhesive resin composition is less than 40% by mass), the adhesion of the adhesive resin layer 15 to other layers such as the sealant layer 16 and the anti-corrosion treatment layer 14 There is a tendency to become easy to reduce.

In addition, the analysis method of the component (c) which is an additive component in the adhesive resin layer 15 can be quantified by, for example, stereoscopic regularity evaluation by nuclear magnetic resonance spectroscopy (NMR).

On the other hand, in the analysis of the component (d), Fourier transform type infrared spectroscopy (FT-IR) can be used, by means of an absorber belonging to the α -olefin branch, and The absorber of the modified polyolefin resin (a) characteristic absorber was used to prepare a calibration curve, and the blend ratio was confirmed.

The adhesive resin layer 15 is in the adhesive resin composition (that is, the modified polyolefin resin (a) component and the macro phase-separated thermoplastic elastomer (b) component) and the additive component (that is, the component (c) and the component ( In addition to d)), various additives such as flame retardants, slipping agents, anti-blocking agents, antioxidants, light stabilizers and tackifiers may also be included as needed. .

The thickness of the adhesive resin layer 15 is not particularly limited, but is preferably from the viewpoint of stress relaxation and moisture/electrolyte penetration. The thickness of the sealant layer 16 is the same or less. That is, from the above viewpoint, the thickness of the adhesive resin layer 15 is, for example, preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 60 μm, and preferably in the range of the sealant layer 16 . Below the thickness.

<Sealant layer 16>

The sealant layer 16 is a layer that imparts encapsulation properties by heat sealing to the exterior material 10. The sealant layer 16 can be a single layer or a plurality of layers.

(Sealant layer in the first invention)

The sealant layer 16 in the first invention comprises a layer formed of a resin composition containing (A) a propylene-ethylene random copolymer of 60 to 95% by mass, and (B) a 1-butyl group. The olefin is a polyolefin elastomer having a melting point of 150 ° C or less of the comonomer of 5 to 40% by mass. The sealant layer 16 may be a layer formed of a resin composition containing (A) a propylene-ethylene random copolymer of 60 to 95% by mass, and (B) a 1-butene group. The polyolefin elastomer having a melting point of 150 ° C or less of the comonomer is 5 to 40% by mass. Hereinafter, each component will be described.

((A) propylene-ethylene random copolymer)

Compared with the propylene-ethylene block copolymer and the propylene homopolymer, the (A) propylene-ethylene random copolymer is excellent in heat sealability at a low temperature, can improve the sealing property related to the electrolytic solution, and can suppress the cause (B) The influence of the polyolefin-based elastomer produces an excessively sealed portion.

In the (A) propylene-ethylene random copolymer, the ethylene content is preferably from 0.1 to 10% by mass, more preferably from 1 to 7% by mass, still more preferably from 2 to 5% by mass. When the ethylene content is 0.1% by mass or more, the melting point lowering effect due to copolymerization of ethylene can be sufficiently obtained, and it can be more and more The tendency to enhance the sealing properties associated with electrolytes. When the ethylene content is 10% by mass or less, the melting point is suppressed from being excessively lowered, and the excessively sealed portion tends to be more sufficiently suppressed. Further, the ethylene content can be calculated from the mixing ratio of the monomers at the time of polymerization. Further, the ethylene content can be measured by infrared absorption spectroscopy (IR method), nuclear magnetic resonance absorption method (13C-NMR method, 1H-NMR method) or the like.

(A) The melting point of the propylene-ethylene random copolymer is preferably from 120 to 145 ° C, more preferably from 125 to 140 ° C. When the melting point is 120 ° C or more, the tendency to form an excessively sealed portion can be more sufficiently suppressed. When the melting point is 145 ° C or lower, the sealing property relating to the electrolytic solution tends to be increased.

The weight average molecular weight of the (A) propylene-ethylene random copolymer is preferably suitably adjusted so that the melting point is within the above range, preferably from 10,000 to 10,000,000, more preferably from 100,000 to 1,000,000.

The (A) propylene-ethylene random copolymer may be an acid-modified one, for example, an acid-modified propylene-ethylene random copolymer obtained by graft-modifying maleic anhydride. By using an acid-modified propylene-ethylene random copolymer, the adhesion to the tab lead can be maintained even without a tab sealant.

(A) The propylene-ethylene random copolymer may be used alone or in combination of two or more.

In the resin composition for forming a sealant layer, the content of the component (A) is 60 to 95% by mass, preferably 60 to 90% by mass, more preferably 60%, based on the total solid content of the resin composition. 85 mass%. Since the content of the component (A) is 60% by mass or more, the use of the component (A) itself The effect is to improve the sealing properties associated with the electrolyte. In addition, when the content of the component (A) is 60% by mass or more, the component (B) is prevented from being excessively present, and the heat resistance of the sealant layer 16 can be suppressed from being lowered, and the excessive sealing portion can be suppressed. . On the other hand, when the content of the component (A) is 95% by mass or less, the content of the component (B) can be 5 mass% or more, and the degassing heat seal due to the component (B) can be sufficiently obtained. The effect of improving the strength.

((B) a polyolefin-based elastomer having a melting point of 150 ° C or less using 1-butene as a comonomer)

(B) A polyolefin-based elastomer having a melting point of 150 ° C or lower, which is a comonomer of 1-butene, contributes to an improvement of the sealing property relating to the electrolyte containing degassing heat seal strength, and contributes to suppression of molding whitening. happened.

(B) The polyolefin-based elastomer may be compatible with the component (A), or may have no compatibility, but preferably contains (B-1) a compatible polyolefin system having compatibility. Both an elastomer and a (B-2) non-miscible polyolefin-based elastomer that does not have compatibility. Here, the compatibility with the component (A) (miscible system) means that the dispersed phase has a size of 1 nm or more and less than 500 nm and is dispersed in the propylene-ethylene random copolymer resin constituting the component (A). The term "non-miscible" does not mean that the dispersed phase has a size of 500 nm or more and less than 20 μm and is dispersed in the propylene-ethylene random copolymer resin constituting the component (A).

The (B-1) phase-soluble polyolefin elastomer may, for example, be a propylene-1-butene random copolymer.

The (B-2) non-miscible polyolefin-based elastomer may, for example, be an ethylene-1-butene random copolymer.

(B) The polyolefin-based elastomer has a melting point of 150 ° C or less, but is preferably 60 to 120 ° C from the viewpoint of suppressing the excessively sealed portion, suppressing the molding whitening, and improving the sealing property relating to the electrolytic solution. It is 65~90 °C. Since the melting point is 150 ° C or less, the sealing property relating to the electrolytic solution can be improved, and in particular, the degassing heat seal strength can be improved. Further, when the melting point is 60 ° C or more, it is advantageous from the viewpoint of suppressing the occurrence of an excessively sealed portion.

(B) The polyolefin-based elastomer may be used singly or in combination of two or more.

In the resin composition for forming a sealant layer, the content of the component (B) is 5 to 40% by mass, preferably 10 to 40% by mass, more preferably 15%, based on the total solid content of the resin composition. 40% by mass. When the content of the component (B) is 5% by mass or more, the sealing property relating to the electrolytic solution can be sufficiently obtained, and in particular, the effect of improving the heat-sealing strength of the degassing is obtained. On the other hand, when the content of the component (B) is 40% by mass or less, it is possible to suppress a decrease in heat resistance of the sealant layer 16 and to suppress generation of an excessively sealed portion.

When the component (B) contains the (B-1) insoluble polyolefin elastomer and the (B-2) incompatible polyolefin elastomer, the content ratio of the two ((B-1) compatible polyolefin system) The elastomer/(B-2) non-miscible polyolefin-based elastomer) is preferably from 0.5 to 3, more preferably from 1 to 2, in terms of mass ratio. When the content ratio is in the above range, the molding whitening resistance and the sealing property with respect to the electrolytic solution can be improved in a well-balanced manner.

(adding ingredients)

The resin composition for forming a sealant layer is the above component (A) and (B) Other components may be further included in addition to the components. For the components other than the components (A) and (B), for example, in order to improve the drawability and workability, other resins such as LDPE (low density polyethylene) may be added. The content of the other resin component to be added is preferably 10% by mass or less based on the total solid content of the resin composition. Further, examples of the components other than the resin include a slip aid, an anti-caking agent, an antioxidant, a light stabilizer, and a flame retardant. The content of the other components other than the resin is preferably 5% by mass or less based on the total solid content of the resin composition.

The thickness of the sealant layer 16 is not particularly limited, and specifically, for example, it is preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 60 μm.

In the sealant layer 16, the presence of 1-butene can be confirmed by classification by FT-IR (Fourier transform infrared spectrophotometer). Further, the content of 1-butene can be obtained by using a resin composition containing a known amount of an elastomer having a known amount of 1-butene, and a characteristic absorption band of the components (A) and (B) ( The transmittance or absorbance of the characteristic absorption band is confirmed by making a calibration curve. Further, the 1-butene content of each of the (B-1)-compatible polyolefin-based elastomer and the (B-2)-insoluble polyolefin-based elastomer can also be similarly characterized by FT-IR. The absorption band was imaged and confirmed by microscopic FT-IR (penetration method) by mapping by absorption of 1-butene. Further, in addition to the FT-IR, the presence and content of 1-butene can also be confirmed by NMR measurement by dissolving the sealant layer 16 with a solvent.

(Sealant layer in the second invention)

The sealant layer 16 in the second invention contains the following resin composition In the formed layer, the resin composition contains (A) a propylene-ethylene random copolymer in an amount of 60 to 95% by mass, and a (B') phase-soluble elastomer having compatibility with the (A) propylene-ethylene random copolymer and And the total amount of the (C) incompatible elastomer which does not have compatibility with the (A) propylene-ethylene random copolymer is 5 to 40% by mass in total. In the above resin composition, the mass ratio of the (C) incompatible elastomer content to the (B') phase-soluble elastomer content is from 0 to 1. Further, the (B') compatible elastomer and the (C) incompatible elastomer have a common comonomer component. Hereinafter, each component will be described.

((A) propylene-ethylene random copolymer)

Compared with the propylene-ethylene block copolymer and the propylene homopolymer, the (A) propylene-ethylene random copolymer is excellent in heat sealability at a low temperature and can improve the sealing property associated with the electrolyte. Further, since the (A) propylene-ethylene random copolymer has low crystallinity, it is possible to suppress volume change due to heat shrinkage, suppress generation of cracks, and improve insulation after molding.

In the (A) propylene-ethylene random copolymer, the ethylene content is preferably from 0.1 to 10% by mass, more preferably from 1 to 7% by mass, still more preferably from 2 to 5% by mass. When the ethylene content is 0.1% by mass or more, the effect of lowering the melting point due to copolymerization of ethylene can be sufficiently obtained, and the sealing property relating to the electrolytic solution tends to be increased. When the ethylene content is 10% by mass or less, it is possible to suppress the melting point from being excessively lowered, and it is more likely to suppress the occurrence of heat fusion (over-sealed portion) other than the sealing portion. Further, the ethylene content can be measured by infrared absorption spectroscopy (IR method), nuclear magnetic resonance absorption method ( ¹³ C-NMR method, ¹ H-NMR method) or the like.

The melting point of the (A) propylene-ethylene random copolymer is preferably from 120 to 145 ° C, more preferably from 125 to 140 ° C. If the melting point is 120 ° C or higher, There is a tendency that the generation of the excessively sealed portion can be more sufficiently suppressed. When the melting point is 145 ° C or lower, the sealing property relating to the electrolytic solution tends to be increased.

The weight average molecular weight of the (A) propylene-ethylene random copolymer is preferably adjusted so that the melting point is within the above range, preferably from 10,000 to 10,000,000, more preferably from 100,000 to 1,000,000.

The (A) propylene-ethylene random copolymer may be an acid-modified one, for example, an acid-modified propylene-ethylene random copolymer obtained by graft-modifying maleic anhydride. By using an acid-modified propylene-ethylene random copolymer, the adhesion to the tab guide can be maintained even without the tab sealant.

(A) The propylene-ethylene random copolymer may be used alone or in combination of two or more.

In the resin composition for forming a sealant layer, the content of the component (A) is 60 to 95% by mass, preferably 70 to 90% by mass, more preferably 70%, based on the total solid content of the resin composition. 85 mass%. When the content of the component (A) is 60% by mass or more, the sealing property of the electrolytic solution can be improved by the effect (melting point, degree of crystallization) of the component (A). In addition, when the content of the component (A) is 60% by mass or more, the (B') component and/or the component (C) are prevented from being excessively present, and the heat resistance of the sealant layer can be suppressed from being lowered. It can suppress the swelling of the electrolyte. On the other hand, when the content of the component (A) is 95% by mass or less, the content of the component (B') and/or the component (C) can be 5% by mass or more in total, and (B') can be obtained. The effect of improving the degassing heat seal strength by the component and/or the component (C).

((B') compatible elastomer)

The (B') compatible elastomer can help to suppress the occurrence of cracks and improve the insulation after molding.

(B') An elastomer having a compatible system of the (A) component. Here, the compatibility with the component (A) (miscible system) means that the dispersed phase has a size of 1 nm or more and less than 500 nm and is dispersed in the propylene-ethylene random copolymer resin constituting the component (A). The term "non-coherent" does not mean that the dispersed phase has a size of 500 nm or more and less than 20 μm and is dispersed in the propylene-ethylene random copolymer resin constituting the component (A).

Examples of the (B')-compatible elastomers include propylene-based elastomers, hydrogenated styrene-based elastomers, and ethylene- α- olefins (the α -olefins have a large carbon number and a high content of α -olefins). ) Elastomers, etc. In the ethylene- α- olefin elastomer, the α -olefin has a carbon number of, for example, 4 or more, and the α -olefin content is, for example, 35 mol% or more. Among them, from the viewpoint of excellent affinity with the component (A), a propylene-based elastomer and a hydrogenated styrene-based elastomer are preferable. Examples of the propylene-based elastomer include Tafmer (manufactured by Mitsui Chemicals, Inc.) of propylene-1-butene random copolymer and Notio (manufactured by Mitsui Chemicals, Inc.) of a nanocrystal structure-controlled elastomer. In addition, examples of the hydrogenated styrene-based elastomer include Tuftec (manufactured by Asahi Kasei Corporation). (B') The compatible elastomers may be used alone or in combination of two or more.

The melting point of the (B') phase-soluble elastomer is preferably 130 ° C or lower, more preferably 60 to 120 ° C, still more preferably 65 to 90 ° C from the viewpoint of improving the insulating properties after molding. Since the melting point is 130 ° C or less, the sealing property related to the electrolyte can be further improved, in particular, the degassing heat sealing property. Moreover, when the melting point is 60 ° C or more, it is advantageous in terms of suppressing generation of cracks and further improving insulation properties after molding.

((C) incompatible elastomer)

(C) The non-miscible elastomer contributes to the improvement of the electrolyte-related sealing properties including the degassing heat seal strength.

(C) An incompatible elastomeric system is an elastomer which does not have compatibility with the component (A). Here, the component (A) does not have a compatibility (non-coherent system), and it means that it is dispersed in the propylene-ethylene random copolymer resin constituting the component (A) in a dispersed phase size of 500 nm or more and less than 20 μm. .

Examples of the (C) non-phase-soluble elastomer include a styrene-based elastomer, an ethylene-based elastomer, a vinyl chloride-based elastomer, a urethane-based elastomer, and a guanamine-based elastomer. Among them, from the viewpoint of excellent affinity with the component (B'), an ethylene-1-butene random copolymer and a styrene-based elastomer are preferable. Moreover, since the swelling by the electrolytic solution is small, an ethylene-1-butene random copolymer (for example, Excellen (manufactured by Sumitomo Chemical Co., Ltd.)) is preferable. (C) The non-compatible elastomer may be used singly or in combination of two or more.

The melting point of the (C) non-compatible elastomer is preferably 130 ° C, more preferably 60 to 120 ° C, still more preferably 65 ° from the viewpoint of improving the insulating properties after molding and the sealing property relating to the electrolytic solution. 90 ° C. Since the melting point is 130 ° C or less, the sealing property related to the electrolyte can be further improved, in particular, the degassing heat seal strength. Further, the melting point is 60° C. or more, which is advantageous in that the occurrence of cracks is suppressed and the insulation property after molding is further enhanced.

In the resin composition for forming a sealant layer, the total content of the (B') compatible elastomer and/or (C) incompatible elastomer is 5 to 40 based on the total solid content of the resin composition. The mass% is preferably 10 to 40% by mass, more preferably 15 to 40% by mass. When the total content of the (B') component and/or the component (C) is 5% by mass or more, the occurrence of cracks can be suppressed and the insulating property after molding can be improved. On the other hand, when the total content of the component (B') and/or the component (C) is 40% by mass or less, it is possible to suppress a decrease in heat resistance of the sealant layer 16 and to suppress swelling due to the electrolyte. The sealing strength and the degassing heat seal strength are reduced.

(C) a mass ratio of the content of the incompatible elastomer to the (B') phase-soluble elastomer ((C) incompatible elastomer / (B') compatible elastomer) is preferably 0 to 1, preferably 0.3~1, more preferably 0.5~1. By setting the mass ratio of the content to the above range, generation of cracks can be suppressed, insulation after molding can be improved, and degassing heat seal strength can be further enhanced.

In the resin composition for forming a sealant layer, the (B') phase-soluble elastomer and the (C) non-phase-soluble elastomer have a common comonomer component. The (B') component and the (C) component are excellent in affinity with the component (A), and the affinity in the interface of the sea-island structure is improved. The solution-based elastomer is preferably a propylene-1-butene random copolymer, and the (C) non-phase-soluble elastomer is preferably an ethylene-1-butene random copolymer. In this case, the common comonomer component is 1-butene. Further, from the same viewpoint and from the viewpoint of stress such as relaxation molding, the (B') phase-soluble elastomer is preferably a hydrogenated styrene-based elastomer, and the (C) non-phase-soluble elastomer is preferably styrene. Elastomers. In this case, the common comonomer component is styrene.

In the sealant layer 16, the presence of a comonomer component such as 1-butene or styrene can be confirmed by classification by FT-IR (Fourier transform infrared spectrophotometer). Further, the content of the comonomer component can be absorbed by using a resin composition in which a known amount of an elastomer containing a known amount of a comonomer component is blended, and the characteristics of the (A) component and the (B') component are absorbed. The penetration or absorbance of the tape is confirmed by making a calibration curve. Further, the content of the comonomer component of each of the (B')-compatible elastomer and the (C) incompatible elastomer can be similarly imaged by the characteristic absorption band of FT-IR. The micro FT-IR (penetration method) was confirmed by mapping by absorption of the comonomer component. Further, in addition to the FT-IR, the presence or content of the comonomer component can be confirmed by NMR measurement by dissolving the sealant layer 16 with a solvent.

(adding ingredients)

The resin composition for forming a sealant layer may further contain other components than the components (A), (B') and (C). For the components other than the component (A), the component (B'), and the component (C), for example, in order to improve the drawability and the processability, other resins such as LDPE (low density polyethylene) may be added. The content of the other resin component to be added is preferably 10% by mass or less based on the total solid content of the resin composition. Further, examples of the components other than the resin include a slip aid, an anti-caking agent, an antioxidant, a light stabilizer, and a flame retardant. The content of the other components other than the resin is preferably 5% by mass or less based on the total solid content of the resin composition.

The thickness of the sealant layer 16 is not particularly limited, but specifically, for example, it is preferably in the range of 5 to 100 μm, more preferably 10 to 60 μm. The scope.

In the above, the preferred embodiment of the exterior material for an electrical storage device of the present invention has been described in detail. However, the present invention is not limited to such a specific embodiment, and is within the scope of the gist of the present invention as described in the claims. Make various changes/changes.

For example, in FIG. 1, the state in which the anti-corrosion treatment layer 14 is formed on the surface of the metal foil layer 13 on the side of the adhesive resin layer 15 is shown, but the anti-corrosion treatment layer 14 may be formed on the metal foil layer 13. The surface on the side of the adhesive layer 12 may be formed on both sides of the metal foil layer 13. When the anti-corrosion treatment layer 14 is formed on both sides of the metal foil layer 13, the structure of the anti-corrosion treatment layer 14 formed on the first adhesive layer 12 side of the metal foil layer 13, and the adhesion formed on the metal foil layer 13 The structure of the anti-corrosion treatment layer 14 on the side of the resin layer 15 may be the same or different.

In addition, in FIG. 1, the metal foil layer 13 and the sealant layer 16 are laminated using the adhesive resin layer 15, but it is also like the exterior material 20 of the electrical storage device shown in FIG. The foil layer 13 and the sealant layer 16 are laminated using the second adhesive layer 17. Hereinafter, the second adhesive layer 17 will be described.

<second adhesive layer 17>

The second adhesive layer 17 is a layer in which the metal foil layer 13 on which the anti-corrosion treatment layer 14 is formed and the sealant layer 16 are adhered. For the second adhesive layer 17, a general adhesive for adhering the metal foil layer to the sealant layer can be used.

When the anti-corrosion treatment layer 14 has a layer containing at least one polymer selected from the group consisting of the above cationic polymer and anionic polymer, the second adhesive layer 17 preferably contains the above polymer A layer of a reactive compound (hereinafter also referred to as "reactive compound"), and a compound having reactivity with the above polymer is contained in the anticorrosive treatment layer 14.

For example, when the corrosion-resistant treatment layer 14 contains a cationic polymer, the second adhesive layer 17 contains a compound reactive with the cationic polymer. When the anticorrosive treatment layer 14 contains an anionic polymer, the second adhesive layer 17 contains a compound reactive with the anionic polymer. Further, when the corrosion-resistant treatment layer 14 contains a cationic polymer and an anionic polymer, the second adhesive layer 17 contains a compound reactive with the cationic polymer and a compound reactive with the anionic polymer. . However, the second adhesive layer 17 does not necessarily need to contain the above two types of compounds, and may also contain a compound reactive with both the cationic polymer and the anionic polymer. Here, "reactive" means that a covalent bond is formed with a cationic polymer or an anionic polymer. Further, the second adhesive layer 17 may further contain an acid-modified polyolefin resin.

The compound having reactivity with the cationic polymer may be selected from the group consisting of a polyfunctional isocyanate compound, a glycidyl compound, and a compound having a carboxyl group. At least one compound of the group of oxazoline group compounds.

Such polyfunctional isocyanate compounds, epoxy propyl compounds, compounds having a carboxyl group, The compound of the oxazoline group is exemplified by a polyfunctional isocyanate compound, a glycidyl compound, a compound having a carboxyl group, which is exemplified as a crosslinking agent for forming a cationic polymer in a crosslinked structure, and has a compound having a carboxyl group. An oxazoline group compound or the like. Among these, a polyfunctional isocyanate compound is preferred because it has high reactivity with a cationic polymer and is likely to form a crosslinked structure.

In the case of a compound reactive with an anionic polymer, it may be selected from the group consisting of a glycidyl group-containing compound and having At least one compound of the group of oxazoline group compounds. In the case of such epoxy propyl compounds, The compound of the oxazoline group may, for example, be an epoxy propyl compound exemplified as a crosslinking agent for forming a cationic polymer as a crosslinked structure, having An oxazoline group compound or the like. Among these, a glycidyl compound is preferred in that the reactivity with the anionic polymer is high.

When the second adhesive layer 17 contains an acid-modified polyolefin resin, the reactive compound is preferably also reactive with an acidic group in the acid-modified polyolefin resin (that is, it forms a covalent bond with an acidic group). Thereby, the adhesion to the anti-corrosion treatment layer 14 is increased. In addition, the acid-modified polyolefin resin has a crosslinked structure, and the solvent resistance of the exterior material 20 is further improved.

The content of the reactive compound is preferably from an equivalent amount to 10 times the amount relative to the acidic group in the acid-modified polyolefin resin. When the amount is more than the same amount, the reactive compound sufficiently reacts with the acidic group in the acid-modified polyolefin resin. On the other hand, if it is more than 10 times the equivalent amount, since the crosslinking reaction with the acid-modified polyolefin resin is sufficiently saturated, there is an unreacted product, and various performance deteriorations are feared.

The acid-modified polyolefin resin is one in which an acid base is introduced into a polyolefin resin. The acidic group may, for example, be a carboxyl group or a sulfonic acid group, and particularly preferably a carboxyl group. As the acid-modified polyolefin resin, the same as those exemplified as the modified polyolefin resin (a) for the adhesive resin layer 15 can be used.

In the second adhesive layer 17, it may also be blended with: a flame retardant, Various additives such as slip agents, anti-caking agents, antioxidants, light stabilizers, and tackifiers.

Further, in a general adhesive for adhering the metal foil layer and the sealant layer, a decane-containing coupling agent may be present. This is due to the fact that the bonding strength is promoted by blending a decane coupling agent to increase the bonding strength. However, if an adhesive containing a decane coupling agent is used, the components other than the decane coupling agent contained in the adhesive layer and the decane coupling agent may be side-reacted due to the type of the functional group contained in the decane coupling agent. The cross-linking reaction of the target has an adverse effect. Therefore, in the adhesive for adhering the metal foil layer to the sealant layer, it is preferred that the decane coupling agent is not contained.

Since the second adhesive layer 17 contains the above-mentioned reactive compound, a covalent bond is formed with the polymer in the anti-corrosion treatment layer 14, and the adhesion strength of the anti-corrosion treatment layer 14 and the second adhesive layer 17 is improved. Thus, it is not necessary to blend the decane coupling agent for the purpose of promoting the adhesion in the second adhesive layer 17, and the second adhesive layer 17 preferably does not contain a decane coupling agent.

Further, the thickness of the second adhesive layer 17 is not particularly limited, and is preferably from 1 to 10 μm, more preferably from 3 to 7 μm, from the viewpoint of obtaining desired adhesive strength and workability.

The structure of the exterior material 20 for power storage devices other than the second adhesive layer 17 is the same as that of the exterior material 10 for power storage devices. Further, in the exterior material 20 for power storage device, the thickness of the sealant layer 16 is adjusted in accordance with the thickness of the second adhesive layer 17. The thickness of the sealant layer 16 in the exterior material 20 for a storage device is not particularly limited, and is, for example, preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 80 μm, still more preferably in the range of 20 to 80 μm. .

Further, in FIGS. 1 and 2, the sealant layer 16 is formed of a single layer, but the sealant layer 16 may be formed of two or more layers. The layers of the plurality of layers forming the sealant layer 16 may be the same or different.

In the second invention, when the sealant layer is formed of a plurality of layers, among the plurality of layers forming the sealant layer, the sealant layer has a surface opposite to the second adhesive layer or the adhesive resin layer as a main surface The layer (the innermost layer of the sealant layer), in other words, the layer which is disposed at a position farthest from the second adhesive layer or the adhesive resin layer among the plurality of layers forming the sealant layer, is preferably the following a layer formed of a resin composition: a resin composition containing (A) a propylene-ethylene random copolymer and not containing a (B') phase-soluble elastomer and (C) a non-phase-soluble elastomer Or a resin composition containing (A) a propylene-ethylene random copolymer and a (B') phase-soluble elastomer and not containing (C) an incompatible elastomer. In this case, in the innermost layer of the sealant layer, the occurrence of cracks during cold forming is more suppressed, and the penetration of the electrolyte into the metal foil layer side is more suppressed, and the insulation after molding can be further improved. In the resin composition of the innermost layer of the sealant layer used in the multilayer structure, in terms of (A) propylene-ethylene random copolymer, (B') phase-soluble elastomer, and (C) incompatible elastomer The same as those described above can be used.

When the sealant layer 16 is formed of two layers, the sealant layer 16 includes the first sealant layer 16a on the side of the metal foil layer 13 and is sealed as in the case of the exterior member 30 for a storage device shown in FIG. The second encapsulant layer 16b of the innermost layer of the agent layer 16.

In the exterior material 30 for a power storage device according to the second aspect of the invention, The first sealant layer 16a is preferably a layer formed of the following resin composition from the viewpoint of further improving the insulating property after molding and the heat-sealing property relating to the electrolyte containing the degassing heat seal strength. The resin composition contains (A) a propylene-ethylene random copolymer in an amount of from 60 to 95% by mass, and a (B') compatible elastomer and/or (C) an incompatible elastomer in an amount of from 5 to 40% by mass; In the resin composition, the content of the (C) non-compatible elastomer is preferably 0 to 1 with respect to the content of the (B') phase-soluble elastomer, and the (B') compatible elastomer and (C) are not. The compatible elastomer preferably has a common comonomer component. In this case, from the viewpoint of further improving the heat sealing property relating to the electrolytic solution, in the resin composition used for the first sealant layer 16a, the content of the (C) incompatible elastomer is relative to (B' The mass ratio of the content of the compatible elastomer is preferably from 0.3 to 1, more preferably from 0.5 to 1.

Further, in the exterior material 30 for a storage device according to the first aspect of the invention, the sealing property of the electrolyte containing the degassing heat seal strength is further improved while suppressing the occurrence of the excessively sealed portion and the occurrence of the molding whitening. The first sealant layer 16a is preferably a layer formed of a resin composition containing (A) a propylene-ethylene random copolymer of 60 to 95% by mass, and (B) 1-butene is a polyolefin-based elastomer having a melting point of 150 ° C or less of a comonomer of 5 to 40% by mass.

The structure of the exterior material 30 for power storage devices other than the first sealant layer 16a and the second sealant layer 16b is the same as that of the exterior material 10 for power storage devices. The thickness of the first sealant layer 16a and the second sealant layer 16b in the exterior material 30 for a storage device is not particularly limited, but the thickness of the second sealant layer 16b is preferably from the viewpoint of improving insulation. It is more than the thickness of the first sealant layer 16a.

1 , 2 and 3 show that the base material layer 11 and the metal foil layer 13 are passed through the first adhesive layer 12, but the base material layer 11 may not pass through the first one. The agent layer 12 is directly formed on the metal foil layer 13 by a coating method. In the present specification, the substrate layer directly formed on the metal foil layer 13 by the coating method is referred to as a coating layer. Further, an anti-corrosion treatment layer 14 may be formed on the surface of the metal foil layer 13 on the side of the coating layer. Hereinafter, the coating layer will be described.

<cover layer>

The coating layer has a function of imparting heat resistance in the sealing step when manufacturing the electricity storage device, and suppressing generation of pinholes which may occur during processing and distribution.

The coating layer is formed of a resin and is directly formed on one surface of the metal foil layer 13 without being passed through an adhesive or the like. The formation of such a coating layer can be formed by applying or coating a resin material to be a coating layer on the metal foil layer 13.

As the resin material forming the coating layer, polyester, a fluorine resin, an acrylic resin or the like can be used, and among them, urethane acrylate is preferable. This is because the coating film composed of the urethane acrylate has a suitable ductility. A two-liquid curing type coating liquid can also be used as the coating liquid containing the resin materials.

The thickness of the coating layer is preferably from 3 μm to 30 μm, more preferably from 5 μm to 20 μm. Since the coating layer is formed directly on the metal foil layer 13, it is also easy to form a structure which is thinner than the conventional material by setting the thickness of the coating layer to 20 μm or less.

[Manufacturing method of exterior materials]

Next, an example of a method of manufacturing the exterior material 10 shown in Fig. 1 will be described. Furthermore, the method of manufacturing the exterior material 10 is not limited to the following method.

The method for producing the exterior material 10 of the present embodiment has a schematic configuration comprising the steps of laminating the anticorrosive treatment layer 14 on the metal foil layer 13 and laminating the base material layer 11 and the metal foil layer 13; Further, a step of laminating the adhesive resin layer 15 and the sealant layer 16 to form a laminate; and a step of heat-treating the obtained laminate as needed.

(Step of laminating the anticorrosive treatment layer 14 to the metal foil layer 13) This step is a step of forming the anticorrosive treatment layer 14 on the metal foil layer 13. The method may be a method in which the metal foil layer 13 is subjected to a degreasing treatment, a hot water modification treatment, an anodizing treatment, a chemical conversion treatment, or a coating agent having an anticorrosive property as described above.

In addition, when the anticorrosive treatment layer 14 is a plurality of layers, for example, a coating liquid (coating agent) constituting the anticorrosive treatment layer on the lower layer side (the side of the metal foil layer 13) is applied to the metal foil layer 13 and burned. After the first layer is formed, a coating liquid (coating agent) constituting the anticorrosive treatment layer on the upper layer side is applied to the first layer, and is fired to form a second layer. Further, the second layer may be formed in a lamination step of the adhesive resin layer 15 and the sealant layer 16 which will be described later.

The degreasing treatment may be carried out by a spray method or a dipping method; the hot water metamorphism treatment and the anodizing treatment may be carried out by a dipping method; and in the case of chemical conversion treatment, a suitable impregnation may be selected depending on the type of chemical conversion treatment. The method, the spray method, the coating method, etc. may be carried out.

For the coating method of the coating agent having corrosion resistance, Various methods such as a gravure coating method, a reverse roll coating method, a roll coating method, and a bar coating method can be used.

As described above, the various treatments may be either one of the two sides or one side of the metal foil, but in the case of single-sided treatment, the treated surface is preferably applied to the side of the layer of the adhesive resin layer 15. Further, the above treatment may be performed on the surface of the base material layer 11 as required.

Further, the coating amount of the coating agent for forming the first layer and the second layer is preferably 0.005 to 0.200 g/m ² , more preferably 0.010 to 0.100 g/m ² .

Further, when drying and curing are required, the drying conditions of the anticorrosive treatment layer 14 to be used may be carried out in a range of a base material temperature of 60 to 300 °C.

(Step of bonding the base material layer 11 and the metal foil layer 13)

This step is a step of bonding the metal foil layer 13 provided with the anti-corrosion treatment layer 14 to the base material layer 11 through the first adhesive layer 12. In the bonding method, the materials constituting the first adhesive layer 12 are bonded together by a method such as dry lamination, solventless lamination, or wet lamination. The first adhesive layer 12 is provided in a range of a dry coating amount of 1 to 10 g/m ² , more preferably 3 to 7 g/m ² .

(Lamination step of the adhesive resin layer 15 and the sealant layer 16)

This step is a step of forming the adhesive resin layer 15 and the sealant layer 16 on the anticorrosive treatment layer 14 formed by the previous step. As a method, a method in which the adhesive resin layer 15 and the sealant layer 16 are sandwich-laminated together using an extrusion laminator can be mentioned. Further, it is also possible to use the tandem lamination and coextrusion of extruding the adhesive resin layer 15 and the sealant layer 16 Law to build layers.

By this step, the sequential lamination of the substrate layer 11 / the first adhesive layer 12 / the metal foil layer 13 / the anti-corrosion treatment layer 14 / the adhesive resin layer 15 / the sealant layer 16 as shown in FIG. 1 can be obtained. There are layers of layers.

Further, the adhesive resin layer 15 may be a material which is dry blended in such a manner as to be a blending composition of the above materials, laminated directly by an extrusion laminator, or may be used beforehand in a single-axis extruder. A melt-kneading device such as a twin-screw extruder or a Brabender mixer is used to laminate the granulated adhesive resin layer 15 which has been subjected to melt blending using an extrusion laminator.

Further, when the multilayer anticorrosive treatment layer 14 is formed, when the extrusion laminator is provided with a unit capable of coating an anchor coat layer, the anticorrosive treatment layer 14 may be coated by the unit. Second floor.

(heat treatment step)

This step is a step of heat-treating the laminate. In the heat treatment step, by heat-treating the laminate, the adhesion between the metal foil layer 13 / the anti-corrosion treatment layer 14 / the adhesive resin layer 15 / the sealant layer 16 is improved, and a more excellent electrolyte resistance can be imparted. The properties and the resistance to hydrofluoric acid are also obtained, and the effect of controlling the crystallization of the adhesive resin layer 15 and the sealant layer 16 and improving the insulating properties after molding can be obtained. Therefore, in this step, heat treatment is preferably performed, which improves the adhesion between the respective layers and is suitable for crystallization of the adhesive resin layer 15 and the sealant layer 16.

In this manner, the exterior material 10 of the present embodiment as shown in Fig. 1 can be manufactured.

Next, for the manufacturing method of the outer material 20 shown in FIG. 2 An example will be explained. Furthermore, the method of manufacturing the exterior material 20 is not limited to the following method.

The method for producing the external material 20 of the present embodiment has a schematic configuration including the steps of laminating the anticorrosive treatment layer 14 on the metal foil layer 13 and the step of laminating the base material layer 11 and the metal foil layer 13 a step of further laminating the sealant layer 16 through the second adhesive layer 17 to form a laminate; and a step of aging the obtained laminate as needed. In addition, the step of bonding the base material layer 11 and the metal foil layer 13 can be carried out in the same manner as the method of manufacturing the exterior material 10 described above.

(Lamination step of the second adhesive layer 17 and the sealant layer 16)

This step is a step of bonding the sealant layer 16 to the side of the anti-corrosion treatment layer 14 of the metal foil layer 13 through the second adhesive layer 17. As for the bonding method, a wet process, a dry lamination, etc. are mentioned.

In the wet process, a solution or dispersion constituting the adhesive of the second adhesive layer 17 is applied to the anti-corrosion treatment layer 14 at a predetermined temperature (when the adhesive contains an acid-modified polyolefin resin) The temperature above the melting point causes the solvent to splash and is burned. Thereafter, the sealant layer 16 is laminated to manufacture the exterior material 20. As the coating method, various coating methods exemplified above can be mentioned.

(maturing process step)

This step is a step of subjecting the laminate to a curing (conservation) treatment. The aging of the metal foil layer 13 / the anti-corrosion treatment layer 14 / the second adhesive layer 17 / the sealant layer 16 can be promoted by aging the laminate. The aging treatment can be carried out at a temperature ranging from room temperature to 100 °C. The curing time is, for example, 1 to 10 days.

In this manner, the exterior material 20 of the present embodiment as shown in Fig. 2 can be manufactured.

Next, an example of a method of manufacturing the exterior material 30 shown in Fig. 3 will be described. Furthermore, the method of manufacturing the exterior material 30 is not limited to the following method.

The method for producing the external material 30 of the present embodiment has a schematic configuration including the steps of laminating the anticorrosive treatment layer 14 on the metal foil layer 13 and the step of bonding the base material layer 11 to the metal foil layer 13 Further, a step of laminating the adhesive resin layer 15, the first sealant layer 16a and the second sealant layer 16b to form a laminate, and a step of heat-treating the obtained laminate as needed.

(Lamination step of the adhesive resin layer 15, the first sealant layer 16a, and the second sealant layer 16b)

This step is a step of forming the adhesive resin layer 15, the first sealant layer 16a, and the second sealant layer 16b on the corrosion-resistant treatment layer 14. As the method, a tandem lamination method or a coextrusion method in which the adhesive resin layer 15 and the first sealant layer 16a and the second sealant layer 16b are extruded using an extrusion laminator can be mentioned.

In this manner, the exterior material 30 of the present embodiment as shown in Fig. 3 can be manufactured.

In the above, the preferred embodiment of the exterior material for a storage device of the present invention and the method for producing the same are described in detail. However, the present invention is not limited to such a specific embodiment, and the gist of the present invention described in the scope of the claims is Various modifications/changes are possible within the scope. Furthermore, when the coating layer is provided in place of the substrate layer 11 and the first adhesive layer 12, the storage is performed. When the exterior material for a device is used, the coating layer can be formed by applying or coating a resin material to be a coating layer on the metal foil layer 13 as described above.

The exterior material for the electrical storage device of the present invention can be suitably used as, for example, a secondary battery such as a lithium ion battery, a nickel hydrogen battery, or a lead storage battery, or an external storage device such as an electrochemical capacitor such as an electric double layer capacitor. material. Among them, the exterior material for a power storage device of the present invention is suitable as an exterior material for a lithium ion battery.

[Examples]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples.

First, the examples and comparative examples relating to the first invention are shown.

[Use materials]

The materials used in Examples 1-1 to 1-8 and Comparative Examples 1-1 to 1-5 are shown below.

<Substrate layer (thickness 25 μm)>

A multilayer stretched film (manufactured by Gunze Co., Ltd.) obtained by coextruding a polyethylene terephthalate (PET) film and a nylon (Ny) film was used.

<First adhesive layer (thickness 4 μm)>

A polyurethane-based adhesive (manufactured by Toyo Ink Co., Ltd.) which is a polyester polyol-based main component and an addition-based curing agent of toluene diisocyanate is used.

<First anticorrosive treatment layer (base material layer side)>

(CL-1-1): A "sodium polyphosphate stabilized cerium oxide sol" adjusted to a solid concentration of 10% by mass using distilled water as a solvent. Furthermore, sodium polyphosphate stabilized cerium oxide sol is relative to cerium oxide 100 The mass fraction was obtained by blending 10 parts by mass of the Na salt of phosphoric acid.

(CL-1-2): 90% by mass of "polyacrylic acid ammonium salt (manufactured by Toagosei Co., Ltd.)" adjusted to a solid concentration of 5 mass% using distilled water as a solvent, and "acrylic acid-isopropenyl group" A composition composed of 10% by mass of oxazoline copolymer (manufactured by Nippon Shokubai Co., Ltd.).

<Metal foil layer (thickness 40 μm)>

A soft aluminum foil (Toyo Aluminium Co., Ltd., "8079 material") which was subjected to annealing and degreasing treatment was used.

<Second anti-corrosion treatment layer (sealant side)>

(CL-1-1): A "sodium polyphosphate stabilized cerium oxide sol" adjusted to a solid concentration of 10% by mass using distilled water as a solvent. Further, the sodium polyphosphate stabilized cerium oxide sol is obtained by blending 10 parts by mass of a Na salt of phosphoric acid with 100 parts by mass of cerium oxide.

(CL-1-3): 90% by mass of "polyallylamine (manufactured by Nitto Bose Co., Ltd.)" adjusted to a solid concentration of 5 mass% using distilled water as a solvent, and "polyglycerol polyepoxypropyl ether" A composition of 10% by mass of Nagase Chemex Co., Ltd.).

<Adhesive resin layer (thickness 15 μm)>

A mixture of the following materials was mixed and used in such a manner that the mass ratio became AR-1:AR-2:AR-3=3:1:1.

(AR-1): An acid-modified polypropylene resin composition (manufactured by Mitsui Chemicals, Inc.) containing a random polypropylene (PP) matrix in which ethylene-propylene rubber was blended as a non-compatible rubber was used.

(AR-2): A propylene- α- olefin copolymer ("Toughcellen H" manufactured by Sumitomo Chemical Co., Ltd.) having an irregular structure was used.

(AR-3): A propylene- α- olefin copolymer ("Tafmer XM" manufactured by Mitsui Chemicals, Inc.) having an isotactic structure was used.

<second adhesive layer (thickness 5 μm)>

An adhesive agent obtained by blending 10 parts by mass of a polyisocyanate compound having a trimeric isocyanate structure (solid content ratio) with respect to 100 parts by mass of a maleic anhydride-modified polyolefin resin dissolved in toluene is used.

<Sealant layer>

A resin composition (SL-1-1~SL-1-12) obtained by mixing the components shown in the following Table 1 with the blending amount (unit: parts by mass) shown in the same table was used. . Furthermore, the details of each component are shown below.

(A) component (random PP): a propylene-ethylene random copolymer having a melting point of 140 ° C ("Prime Polypro" manufactured by Prime Polymer Co., Ltd.).

(B-1) component (propylene-1-butene): a propylene-1-butene random copolymer elastomer having a melting point of 85 ° C which is compatible with the component (A) (Tafmer XM, manufactured by Mitsui Chemicals, Inc.) ).

(B-2) component (ethylene-1-butene): an ethylene-1-butene random copolymer elastomer having a melting point of 75 ° C which is not compatible with the component (A) ("Suite", manufactured by Sumitomo Chemical Co., Ltd. ).

Hydrogenated styrene-based rubber: a hydrogenated styrene-based thermoplastic elastomer ("Tuftec", manufactured by Asahi Kasei Corporation) having compatibility with the component (A).

Ethylene-propylene: an ethylene-propylene copolymer elastomer (manufactured by Mitsui Chemicals, Inc., "Tafmer A") which is not compatible with the component (A).

[Example 1-1]

First, the first anti-corrosion treatment layer is provided on the metal foil layer in the following order. That is, (CL-1-1) was applied to one side of the metal foil layer by a micro gravure coating method so that the dry coating amount was 70 mg/m ² , and the baking treatment was performed at 200 ° C in the drying unit. . Next, (CL-1-2) was applied to the obtained layer by a microgravure coating method so that the dry coating amount became 20 mg/m ² , whereby (CL-1-1) and The composite layer composed of CL-1-2) is used as the first anti-corrosion treatment layer. This composite layer exhibits corrosion resistance by combining the two types of (CL-1-1) and (CL-1-2).

Next, (CL-1-1) was applied to the other side of the metal foil layer by a micro gravure coating method so that the dry coating amount became 70 mg/m ² , and it was baked at 200 ° C in a drying unit. Connected to the process. Next, (CL-1-3) was applied to the obtained layer by a microgravure coating method so that the dry coating amount became 20 mg/m ² , whereby (CL-1-1) and (CL-1-1) were formed. The composite layer composed of CL-1-3) serves as a second anticorrosive treatment layer. The composite layer is a composite of (CL-1-1) and (CL-1-3), and exhibits corrosion resistance.

Next, the first anti-corrosion treatment layer side of the metal foil layer provided with the first and second anti-corrosion treatment layers is formed by a dry lamination method using a polyurethane adhesive (first adhesive layer) Attach to the substrate layer. This was placed in a winding-out portion of an extrusion laminator, and was coextruded by a processing condition of 290 ° C and 100 m/min in the order of an adhesive resin layer (thickness: 15 μm) and a sealant layer (thickness: 30 μm). The layer is laminated on the second anti-corrosion treatment layer. Further, the adhesive resin layer and the sealant layer were previously prepared by using a twin-screw extruder to prepare a composite of various materials, and were subjected to the step of water cooling/pelletization for the above extrusion lamination. The resin composition (SL-1-1) was used for the formation of the sealant layer.

The laminate obtained in this manner was subjected to heat treatment by thermal lamination so that the maximum reaching temperature of the laminate was 190 ° C, and the exterior material of the example 1-1 (base material layer / An adhesive layer/first anticorrosive treatment layer/metal foil layer/second anticorrosive treatment layer/layer of the adhesive resin layer/sealant layer).

[Examples 1-2 to 1-7]

The same procedure as in Example 1-1 except that the resin composition used for the formation of the sealant layer was changed to (SL-1-2) to (SL-1-7) (any thickness was 30 μm). The exterior materials of Examples 1-2 to 1-7 were produced by the ground.

[Examples 1-8]

In the same manner as in Example 1-1, a laminate of the base material layer/first adhesive layer/first corrosion-resistant layer/metal foil layer/second corrosion-resistant layer was produced. Next, the adhesive (second adhesive layer) is applied to the second anti-corrosion treatment layer by dry lamination method by dry lamination method with a dry coating amount of 4 to 5 g/m ² , and dried. After the film is formed, a sealant layer is attached. As the sealant layer, an unstretched cast film obtained by using a resin composition (SL-1-1) to have a thickness of 45 μm and subjected to corona treatment on the adhesive bonding surface was used. Thereafter, the aging was carried out at 40 ° C for 5 days to produce the exterior material of Example 1-8 (base material layer / first adhesive layer / first anti-corrosion treatment layer / metal foil layer / second anti-corrosion treatment) Layer/secondary adhesive layer/layer of sealant layer).

[Comparative Example 1-1~1-5]

The same procedure as in Example 1-1 except that the resin composition used for the formation of the sealant layer was changed to (SL-1-8) to (SL-1-12) (any thickness was 30 μm). The exterior materials of Comparative Examples 1-1 to 1-5 were produced by the ground.

<evaluation>

The following evaluation tests were carried out on the external materials obtained in Examples 1-1 to 1-8 and Comparative Examples 1-1 to 1-5.

(electrolyte lamination strength)

The following electrolyte solution was filled in a Teflon (registered trademark) container: LiPF _{6 was} added to a mixed solution of ethylene carbonate/diethyl carbonate/dimethyl carbonate = 1/1/1 (mass ratio) to make 1 M. A sample of 15 mm × 100 mm of the cut outer material was placed therein, and the plug was placed at 85 ° C for 24 hours. Thereafter, the mixture was washed together, and the laminate strength (T-peel strength) between the metal foil layer/adjacent resin layer or the metal foil layer/secondary adhesive layer was measured using a testing machine (manufactured by INSTRON Co., Ltd.). The test procedure was carried out in accordance with JIS K6854 at a peeling speed of 50 mm/min under a 23 ° C, 50% RH gas atmosphere. Based on the results, evaluation was performed based on the following criteria.

A: Lamination strength exceeds 12N/15mm

B: Lamination strength is 10N/15mm or more and 12N/15mm or less

C: Lamination strength is 6N/15mm or more and less than 10N/15mm

D: Lamination strength is lower than 6N/15mm

(electrolyte heat seal strength)

A sample having a cut outer casing of 60 mm × 120 mm was folded in half, and one side was heat-sealed at 190 ° C, 0.5 MPa, and 3 sec with a sealing bar of 10 mm width. Thereafter, 1 ml of the following electrolyte solution was injected into the remaining two sides and heat-sealed to form a bag-shaped exterior material: in ethylene carbonate/diethyl carbonate/dimethyl carbonate = 1/1/1 ( The mixed solution of the mass ratio) was added to LiPF _{6 to} make 1 M. After the obtained capsule was stored at 60 ° C for 24 hours, the first side of the heat seal was cut into a width of 15 mm (see FIG. 4 ), and the seal strength (T-peel strength) was measured using a tester (manufactured by INSTRON). The test procedure was carried out in accordance with JIS K6854 at a peeling speed of 50 mm/min under a 23 ° C, 50% RH gas atmosphere. Based on the results, evaluation was performed based on the following criteria.

A: The sealing strength is 100N/15mm or more, and the burst width exceeds 10mm.

B: The sealing strength is 100N/15mm or more, and the burst width is 5~10mm.

C: Sealing strength is 80N/15mm or more and less than 100N/15mm

D: sealing strength is lower than 80N/15mm

(sealed appearance)

In the evaluation of the heat-sealing strength of the electrolytic solution, in the sealed portion (the strength measuring portion of FIG. 4) after heat sealing at 190 ° C, 0.5 MPa, and 3 sec, whether or not there is no inner layer other than the portion where the sealing rod is in contact dense Confirmation of the over-sealed portion of the sealant side. Based on the results, evaluation was performed based on the following criteria. The excessively sealed portion has a possibility of being thinned with the seal, and has a possibility of reducing the internal volume of the unit body, and is highly likely to have an influence on battery performance and insulation. Therefore, it is preferred that there is no over-sealed portion.

A: There is no over-sealed part, but a uniform sealing part

D: There is an over-sealed part

(degassing heat seal strength)

After the sample having the cut outer casing of 75 mm × 150 mm was folded into 37.5 mm × 150 mm (see Fig. 5 (a)), one of the 150 mm side and the 37.5 mm side was heat-sealed, and the bag was formed. Thereafter, 5 ml of the following electrolyte solution was injected into the capsule: LiPF _{6 was} added to a mixed solution of ethylene carbonate/diethyl carbonate/dimethyl carbonate = 1/1/1 (mass ratio) to make 1 M, and The other of the 37.5 mm sides was heat-sealed to obtain a capsule sealed by the sealing portion S1. After the capsule was stored at 60° C. for 24 hours, the center portion of the capsule was heat-sealed at 190° C., 0.3 MPa, and 2 sec in a state containing the electrolytic solution (degassing sealing portion S2, see FIG. 5( b )). . In order to stabilize the sealing portion, the region including the deaerating sealing portion S2 was cut to a width of 15 mm after being stored at room temperature for 24 hours (see FIG. 5(c)), and the heat sealing strength was measured using a testing machine (manufactured by INSTRON Co., Ltd.). (T-peel strength). The test procedure was carried out in accordance with JIS K6854 at a peeling speed of 50 mm/min under a 23 ° C, 50% RH gas atmosphere. Based on the results, evaluation was performed based on the following criteria.

A: The sealing strength is 80N/15mm or more

B: Sealing strength is 60N/15mm or more and less than 80N/15mm

C: Sealing strength is 40N/15mm or more and less than 60N/15mm

D: sealing strength is lower than 40N/15mm

(forming whitening)

The normal sample of the exterior material and the sample stored at 60 ° C for one week were cut into 120 mm × 200 mm, and placed in a mold for cold forming so that the sealant layer was in contact with the convex portion of the molding machine, and the molding speed was 10 mm/sec. 5mm deep extension. Thereafter, whitening of the belt side of the film which is the most stretched film was observed. The mold used was a molding area of 80 mm × 70 mm (corner type) and a punch corner radius (RCP) of 1.0 mm. Based on the results, evaluation was performed based on the following criteria. In addition, when the evaluation is C or more, it can be said that there is no problem in practical use.

A: Normal samples and samples kept at 60 ° C for 1 week are not whitened.

B: The sample in the normal state was not whitened, and the sample stored at 60 ° C for 1 week was slightly whitened.

C: Sample whitening in the normal sample with slight whitening and storage at 60 ° C for 1 week

D: whitening of the sample in the normal state

(comprehensive quality)

The results of the above evaluations are shown in Table 2. In Table 2 below, if there is no D evaluator in each evaluation result, it can be said that the overall quality is excellent.

As is clear from the results shown in Table 2, (SL-1-1) to (SL-1-7) were used as the resin composition for forming the sealant layer, except for Examples 1-1 to 1-8. The material is whitened and the sealing appearance is good, and the lamination strength and sealing strength (electrolyte lamination strength, electrolyte heat sealing strength and degassing heat sealing strength) related to the electrolyte are improved. On the other hand, it was confirmed that the exterior materials of Comparative Examples 1-1, 1-4, and 1-5 were excellent in forming whitening and sealing appearance, but were inferior in lamination strength and sealing strength with respect to the electrolytic solution. Further, it was confirmed that the exterior materials of Comparative Examples 1-2 and 1-3 were excellent in lamination strength and sealing strength with respect to the electrolytic solution, but were poor in forming whitening or sealing appearance.

Next, examples and comparative examples relating to the second invention will be described.

[Use materials]

The materials used in Examples 2-1 to 2-19 and Comparative Examples 2-1 to 2-5 are shown below.

<Substrate layer (thickness 25 μm)>

A multilayer stretched film (manufactured by Gunze Co., Ltd.) obtained by coextruding a polyethylene terephthalate (PET) film and a nylon (Ny) film was used.

<First adhesive layer (thickness 4 μm)>

A polyurethane-based adhesive (manufactured by Toyo Ink Co., Ltd.) which is a polyester polyol-based main component and an addition-based curing agent of toluene diisocyanate is used.

<First anticorrosive treatment layer (base material layer side)>

It is the same as the second anticorrosive treatment layer on the side of the sealant layer to be described later.

<Metal foil layer (thickness 40 μm)>

A soft aluminum foil that has been annealed and degreased (Toyo Aluminum (Toyo) Aluminium) company system, "8079 material").

<Second anti-corrosion treatment layer (sealant side)>

(CL-2-1): A "sodium polyphosphate stabilized cerium oxide sol" adjusted to a solid concentration of 10% by mass using distilled water as a solvent. Further, the sodium polyphosphate-stabilized cerium oxide sol is obtained by blending 10 parts by mass of a Na salt of phosphoric acid with respect to 100 parts by mass of cerium oxide.

(CL-2-2): 90% by mass of "polyallylamine (manufactured by Nitto Bose Co., Ltd.)" adjusted to a solid concentration of 5 mass% using distilled water as a solvent, and "polyglycerol polyepoxypropyl ether" A composition of 10% by mass of Nagase Chemex Co., Ltd.).

(CL-2-3): The following chemical conversion treatment agent was used: a water-soluble phenol resin (manufactured by Sumitomo Bakelite Co., Ltd.) adjusted to a solid content concentration of 1% by mass using a 1% by mass aqueous solution of phosphoric acid as a solvent The chromium fluoride (CrF ₃ ) concentration was adjusted so that the amount of Cr present in the final dried film became 10 mg/m ² .

<Adhesive resin layer>

A mixture of the following materials was mixed and used in such a manner that the mass ratio became AR-1:AR-2:AR-3=3:1:1.

(AR-1): An acid-modified polypropylene resin composition (manufactured by Mitsui Chemicals, Inc.) containing a random polypropylene (PP) matrix in which ethylene-propylene rubber was blended as a non-compatible rubber was used.

(AR-2): A propylene- α- olefin copolymer ("Toughcellen H" manufactured by Sumitomo Chemical Co., Ltd.) having an irregular structure was used.

(AR-3): A propylene- α- olefin copolymer ("Tafmer XM" manufactured by Mitsui Chemicals, Inc.) having an isotactic structure was used.

<second adhesive layer (thickness 3 μm)>

An adhesive agent obtained by blending 10 parts by mass of a polyisocyanate compound having a trimeric isocyanate structure (solid content ratio) with respect to 100 parts by mass of a maleic anhydride-modified polyolefin resin dissolved in toluene is used.

<Sealant layer>

A resin composition (SL-2-1 to SL-2-12) obtained by mixing the components shown in the following Table 3 with the blending amount (unit: parts by mass) shown in the same table was used. . Furthermore, the details of each component are shown below.

‧(A) ingredients

(random PP): a propylene-ethylene random copolymer having a melting point of 140 ° C ("Prime Polypro", manufactured by Prime Polymer Co., Ltd.).

‧(B’) ingredients

(Propylene-1-butene): a propylene-1-butene random copolymer elastomer (manufactured by Mitsui Chemicals, Inc., "Tafmer XM") having a melting point of 75 ° C which is compatible with the component (A).

(Hydrogenated styrene-based elastomer): a hydrogenated styrene-based thermoplastic elastomer ("Tuftec", manufactured by Asahi Kasei Corporation) having compatibility with the component (A).

‧(C) ingredients

(Ethylene-1-butene): an ethylene-1-butene random copolymer elastomer (manufactured by Sumitomo Chemical Co., Ltd., "Excellen") having a melting point of 70 ° C which is not compatible with the component (A).

(Styrene-based elastomer): a styrene-butadiene copolymer elastomer ("Asaflex" manufactured by Asahi Kasei Corporation) which does not have compatibility with the component (A).

[Example 2-1]

First, the first and second anti-corrosion treatment layers are provided on the metal foil layer in the following order. That is, (CL-2-1) was applied to both surfaces of the metal foil layer by a micro gravure coating method so that the dry coating amount was 70 mg/m ² , and baking was performed at 200 ° C in the drying unit. deal with. Next, (CL-2-2) was applied onto the obtained layer by a microgravure coating method so that the dry coating amount became 20 mg/m ² , whereby (CL-2-1) and (CL-2) were formed. The composite layer composed of CL-2-2) serves as the first and second corrosion-resistant treatment layers. This composite layer exhibits corrosion resistance by combining the two types of (CL-2-1) and (CL-2-2).

Next, the first anti-corrosion treatment layer side of the metal foil layer provided with the first and second anti-corrosion treatment layers is formed by a dry lamination method using a polyurethane adhesive (first adhesive layer) Attach to the substrate layer. This was placed in the unwinding portion of the extrusion laminator, and was coextruded in the order of the adhesive resin layer (thickness: 12 μm) and the sealant layer (thickness: 23 μm) by processing conditions at 290 ° C and 100 m/min. Laminated in the second anti-corrosion treatment layer on. Further, the adhesive resin layer and the sealant layer were previously prepared by using a twin-screw extruder to prepare a composite of various materials, and were subjected to the step of water cooling/pelletization for the above extrusion lamination. The resin composition (SL-2-1) was used for the formation of the sealant layer.

The laminate obtained in this manner was subjected to heat treatment by thermal lamination so that the maximum reaching temperature of the laminate was 190 ° C, and the exterior material (base material layer / first) was produced. An adhesive layer/first anticorrosive treatment layer/metal foil layer/second anticorrosive treatment layer/layer of the adhesive resin layer/sealant layer).

[Examples 2-2 to 2-7]

In the same manner as in Example 2-1 except that the resin composition used for the formation of the sealant layer was changed to (SL-2-2) to (SL-2-7), respectively (any thickness was 23 μm). The exterior materials of Examples 2-2 to 2-7 were produced.

[Example 2-8]

In the same manner as in Example 2-1, a laminate of the base material layer/first adhesive layer/first corrosion-resistant layer/metal foil layer/second corrosion-resistant layer was produced. This was placed in the unwinding portion of the extrusion laminator, and the adhesive resin layer (thickness: 10 μm), the first sealant layer (metal foil layer side, thickness: 10 μm), and the second sealant layer (inner layer, thickness) 15 μm) was laminated on the second anticorrosive treatment layer by co-extrusion at 290 ° C and a processing condition of 100 m / min. Further, the adhesive resin layer, the first sealant layer, and the second sealant layer are prepared by using a twin-screw extruder to prepare a composite of various materials and then subjected to a water cooling/pelletization step. The laminate was extruded as described above. The first sealant layer is formed by using a resin composition (SL-2-5), and the second sealant layer was formed by using a resin composition (SL-2-2).

[Embodiment 2-9]

The same procedure as in Example 2-8 was carried out except that the resin composition used for forming the first sealant layer was changed to (SL-2-7) (thickness: 10 μm), and Examples 2 to 9 were produced. Exterior materials.

[Example 2-10]

The exterior material of Example 2-10 was produced in the same manner as in Example 2-2 except that the thickness of the adhesive resin layer was changed to 10 μm and the thickness of the sealant layer was changed to 20 μm.

[Embodiment 2-11]

In the same manner as in Example 2-1, a laminate of the base material layer/first adhesive layer/first corrosion-resistant layer/metal foil layer/second corrosion-resistant layer was produced. Next, an adhesive (second adhesive layer) is applied to the second anticorrosive treatment layer by a dry lamination method at a dry coating amount of 4 to 5 g/m ² , and dried and formed into a film. A sealant layer is attached. As the sealant layer, an unstretched cast film obtained by forming a film of a resin composition (SL-2-2) to a thickness of 30 μm and performing corona treatment on the adhesive bonding surface was used. Thereafter, the aging was carried out at 40 ° C for 5 days to produce the exterior material of Example 2-11 (base material layer / first adhesive layer / first anti-corrosion treatment layer / metal foil layer / second anti-corrosion treatment) Layer/secondary adhesive layer/layer of sealant layer).

[Example 2-12]

The exterior materials of Examples 2 to 12 were produced in the same manner as in Example 2-2 except that the first and second corrosion-resistant treatment layers were provided in the following order. In Example 2-12, (CL-2-3) was applied to both sides of the metal foil layer by a micro gravure coating method so that the dry coating amount was 30 mg/m ² , and in the drying unit, The burn-in treatment was carried out at 200 °C. Next, (CL-2-2) was applied to the obtained layer by a micro gravure coating method so that the dry coating amount became 20 mg/m ² , thereby forming (CL-2-3) and ( The composite layer composed of CL-2-2) serves as the first and second corrosion-resistant treatment layers. This composite layer exhibits corrosion resistance by combining the two types of (CL-2-3) and (CL-2-2).

[Example 2-13]

The exterior material of Example 2-13 was produced in the same manner as in Example 2-11 except that the first and second anticorrosive treatment layers were provided in the following order. In Example 2-13, (CL-2-3) was applied to both sides of the metal foil layer by a micro gravure coating method so that the dry coating amount was 30 mg/m ² , and in the drying unit, The burn-in treatment was carried out at 200 °C. Next, (CL-2-2) was applied to the obtained layer by a micro gravure coating method so that the dry coating amount became 20 mg/m ² , thereby forming (CL-2-3) and ( The composite layer composed of CL-2-2) serves as the first and second corrosion-resistant treatment layers. This composite layer exhibits corrosion resistance by combining the two types of (CL-2-3) and (CL-2-2).

[Examples 2-14]

The exterior material of Example 2-14 was produced in the same manner as in Example 2-2 except that the thickness of the adhesive resin layer was changed to 13 μm and the thickness of the sealant layer was changed to 27 μm.

[Embodiment 2-15]

In addition to changing the thickness of the adhesive resin layer to 13 μm, and sealing The exterior material of Example 2-15 was produced in the same manner as in Example 2-5 except that the thickness of the agent layer was changed to 27 μm.

[Embodiment 2-16]

The exterior material of Example 2-16 was produced in the same manner as in Example 2-2 except that the thickness of the adhesive resin layer was changed to 15 μm and the thickness of the sealant layer was changed to 30 μm.

[Examples 2-17]

The exterior material of Example 2-17 was produced in the same manner as in Example 2-5 except that the thickness of the adhesive resin layer was changed to 15 μm and the thickness of the sealant layer was changed to 30 μm.

[Embodiment 2-18]

The exterior material of Example 2-18 was produced in the same manner as in Example 2-2 except that the thickness of the adhesive resin layer was changed to 27 μm and the thickness of the sealant layer was changed to 53 μm.

[Embodiment 2-19]

The exterior material of Example 2-19 was produced in the same manner as in Example 2-5 except that the thickness of the adhesive resin layer was changed to 27 μm and the thickness of the sealant layer was changed to 53 μm.

[Comparative Example 2-1~2-5]

The same procedure as in Example 2-1 except that the resin composition used for the formation of the sealant layer was changed to (SL-2-8) to (SL-2-12) (both of which were 23 μm) The exterior materials of Comparative Examples 2-1 to 2-5 were produced.

<evaluation>

In addition to those obtained in Examples 2-1 to 2-19 and Comparative Examples 2-1 to 2-5 The following evaluation tests were carried out for the materials.

(electrolyte lamination strength)

The following electrolyte solution was filled in a Teflon (registered trademark) container: LiPF _{6 was} added to a mixed solution of ethylene carbonate/diethyl carbonate/dimethyl carbonate = 1/1/1 (mass ratio) to make 1 M. A sample of 15 mm × 100 mm of the cut outer material was placed therein, and the plug was placed at 85 ° C for 24 hours. Thereafter, the mixture was washed together, and the laminate strength (T-peel strength) between the metal foil layer/adjacent resin layer or the metal foil layer/secondary adhesive layer was measured using a testing machine (manufactured by INSTRON Co., Ltd.). The test procedure was carried out in accordance with JIS K6854 at a peeling speed of 50 mm/min under a 23 ° C, 50% RH gas atmosphere. Based on the results, evaluation was performed based on the following criteria.

A: Lamination strength exceeds 9N/15mm

B: Lamination strength is 7N/15mm or more and 9N/15mm or less

C: Lamination strength is 5N/15mm or more and less than 7N/15mm

D: Lamination strength is lower than 5N/15mm

(electrolyte heat seal strength)

A sample having a cut outer casing of 60 mm × 120 mm was folded in half, and one side was heat-sealed at 190 ° C, 0.5 MPa, and 3 sec with a sealing bar of 10 mm width. Thereafter, 2 ml of the following electrolyte solution was injected into the remaining two sides and heat-sealed to form a bag-shaped exterior material: in ethylene carbonate/diethyl carbonate/dimethyl carbonate = 1/1/1 ( The mixed solution of the mass ratio) was added to LiPF _{6 to} make 1 M. After the obtained capsule was stored at 60 ° C for 24 hours, the first side of the heat seal was cut into a width of 15 mm (see FIG. 4 ), and the seal strength (T-peel strength) was measured using a tester (manufactured by INSTRON). The test procedure was carried out in accordance with JIS K6854 at a peeling speed of 50 mm/min under a 23 ° C, 50% RH gas atmosphere. Based on the results, evaluation was performed based on the following criteria.

A: The sealing strength is 80N/15mm or more, and the burst width exceeds 5mm.

B: The sealing strength is 80N/15mm or more, and the burst width is 3~5mm.

C: Sealing strength is 60N/15mm or more and less than 80N/15mm

D: sealing strength is lower than 60N/15mm

(degassing heat seal strength)

After the sample having the cut outer casing of 75 mm × 150 mm was folded into 37.5 mm × 150 mm (see Fig. 5 (a)), one of the 150 mm side and the 37.5 mm side was heat-sealed, and the bag was formed. Thereafter, 5 ml of the following electrolyte solution was injected into the capsule: LiPF _{6 was} added to a mixed solution of ethylene carbonate/diethyl carbonate/dimethyl carbonate = 1/1/1 (mass ratio) to make 1 M, and The other of the 37.5 mm sides was heat-sealed to obtain a capsule sealed by the sealing portion S1. After the capsule was stored at 60° C. for 24 hours, the center portion of the capsule was heat-sealed at 190° C., 0.3 MPa, and 2 sec in a state containing the electrolytic solution (degassing sealing portion S2, see FIG. 5( b )). . In order to stabilize the sealing portion, the region including the deaerating sealing portion S2 was cut to a width of 15 mm after being stored at room temperature for 24 hours (see FIG. 5(c)), and the heat sealing strength was measured using a testing machine (manufactured by INSTRON Co., Ltd.). (T-peel strength). The test procedure was carried out in accordance with JIS K6854 at a peeling speed of 50 mm/min under a 23 ° C, 50% RH gas atmosphere. Based on the results, evaluation was performed based on the following criteria.

A: The sealing strength is 60N/15mm or more

B: Sealing strength is 40N/15mm or more and less than 60N/15mm

C: Sealing strength is 30N/15mm or more and less than 40N/15mm

D: sealing strength is lower than 30N/15mm

(insulation after molding)

The sample 40 having a cut outer casing of 120 mm × 200 mm was placed in a mold for cold forming so that the sealant layer was in contact with the convex portion of the molding machine, and a deep extension of 2.5 mm was formed at a molding speed of 15 mm/sec to form a deep extension portion. After 41, the fold is 120 mm × 100 mm (see Fig. 6 (a)). Next, the upper side portion 104 of 100 mm is heat-sealed in a state in which the protruding piece 42 and the tab sealant 43 are interposed (see FIG. 6(b)), and the side portion 45 of 120 mm is heat-sealed. Bag making was performed (refer to Fig. 6 (c)). Thereafter, in order to bring the electrodes into contact, a part of the outer layer of the sample 40 is scraped off to form the exposed portion 46 of the metal foil layer (see FIG. 6(d)). Next, 5 ml of the following electrolyte solution was injected into the capsule: LiPF _{6 was} added to a mixed solution of ethylene carbonate / diethyl carbonate / dimethyl carbonate = 1 / 1 / 1 (mass ratio) to become 1 M; The lower side portion 47 of 100 mm is sealed by heat sealing (refer to Fig. 6(e)). Thereafter, the electrodes 48a and 48b are connected to the exposed portion 46 of the tab 42 and the metal foil layer, respectively, and 25V is applied using a withstanding voltage/insulation resistance tester ("SKSUSUI", "TOS9201"). The resistance value at this time was measured (refer to Fig. 6 (f)). The mold used was a molding area of 80 mm × 70 mm (corner type) and a punch corner radius (RCP) of 1.0 mm. Based on the results, evaluation was performed based on the following criteria.

A: The resistance value exceeds 200MΩ

B: The resistance value is 100 MΩ or more and 200 MΩ or less.

C: The resistance value is 30 MΩ or more and less than 100 MΩ.

D: Resistance value is lower than 30MΩ

(comprehensive quality)

The results of the above evaluations are shown in Table 4. In Table 4 below, if there is no D evaluator in each evaluation result, it can be said that the overall quality is excellent.

As is clear from the results shown in Table 4, (SL-2-1) to (SL-2-7) were used as the resin compositions for forming the sealant layer in Examples 2-1 to 2-19. The exterior material is excellent in insulation properties after molding, lamination strength and sealing strength (electrolyte lamination strength, electrolyte heat seal strength, and deaeration heat seal strength) with respect to the electrolyte. On the other hand, it was confirmed that the exterior materials of Comparative Examples 2-1, 2-2, 2-4, and 2-5 have good lamination strength and sealing strength with respect to the electrolytic solution, but the insulation after molding. Poor sex. Further, it was confirmed that the exterior material of Comparative Example 2-3 was excellent in insulation properties after molding, but the deaeration heat seal strength was inferior.

Claims (17)

An exterior material for a power storage device comprising a metal foil layer, a second adhesive layer or the like in which at least a base material layer, a first adhesive layer, and an anticorrosive treatment layer are provided on one or both surfaces in the following order An outer covering material for a power storage device having a structure of a resin layer and a sealant layer, wherein the sealant layer contains a layer formed of a resin composition containing (A) propylene-ethylene random 60 to 95% by mass of the copolymer and 5 to 40% by mass of the polyolefin-based elastomer having a melting point of 150 ° C or less which is a comonomer of (B) 1-butene. The exterior material for a storage device according to claim 1, wherein the (B) polyolefin-based elastomer comprises (B-1) a compatible polyolefin system which is compatible with the (A) propylene-ethylene random copolymer. An elastomer and a (B-2) incompatible polyolefin elastomer which is not compatible with the above (A) propylene-ethylene random copolymer. The exterior material for a storage device according to claim 2, wherein the (B-1) phase-soluble polyolefin elastomer is a propylene-1-butene random copolymer, and the (B-2) non-phase-soluble polyolefin system The elastomer is an ethylene-1-butene random copolymer. The exterior material for a storage device according to any one of claims 1 to 3, wherein the metal foil layer and the sealant layer pass through the adhesive resin layer, and the adhesive resin layer contains modified polypropylene as a bonding property. Resin composition. The exterior material for a storage device according to any one of claims 1 to 4, wherein the metal foil layer and the sealant layer are permeable to the adhesive layer, and The adhesive resin layer contains an adhesive resin composition, a polypropylene having an irregular structure, and/or an propylene-α-olefin copolymer having an irregular structure. The exterior material for a storage device according to claim 5, wherein the adhesive resin layer further comprises an isotactic structure of a propylene-α-olefin copolymer. The exterior material for a storage device according to any one of claims 1 to 3, wherein the anti-corrosion treatment layer is provided at least on the side of the sealant layer of the metal foil layer, and the anti-corrosion treatment layer comprises: At least one polymer of the group of the polymer and the anionic polymer, the metal foil layer and the sealant layer are transmitted through the second adhesive layer, and the second adhesive layer includes and is in contact with the first layer The aforementioned polymer contained in the foregoing anticorrosive treatment layer of the second adhesive layer has a reactive compound. The exterior material for a storage device according to claim 7, wherein the second adhesive layer comprises an acid-modified polyolefin resin. The exterior material for a storage device according to any one of claims 1 to 8, wherein the anticorrosive treatment layer contains a rare earth element oxide and is 1 to 100 parts by mass based on 100 parts by mass of the rare earth element oxide. Phosphoric acid or phosphate. An exterior material for a power storage device comprising a metal foil layer, a second adhesive layer or the like in which at least a base material layer, a first adhesive layer, and an anticorrosive treatment layer are provided on one or both surfaces in the following order An exterior material for a power storage device having a structure in which a resin layer and a sealant layer are formed, wherein the sealant layer contains a layer formed of the following resin composition The resin composition contains (A) a propylene-ethylene random copolymer in an amount of 60 to 95% by mass, and a (B') compatible elastomer which is compatible with the above (A) propylene-ethylene random copolymer and/or The (C) incompatible elastomer having no compatibility with the above (A) propylene-ethylene random copolymer is 5 to 40% by mass in total; and in the above resin composition, the content of the (C) incompatible elastomer is The mass ratio of the content of the (B')-compatible elastomer is 0 to 1, and the (B')-compatible elastomer and the (C) non-phase-soluble elastomer have a common comonomer component. The exterior material for a storage device according to claim 10, wherein the (B') phase-soluble elastomer is a propylene-1-butene random copolymer, and the (C) non-phase-soluble elastomer is ethylene-1-butene. Random copolymer. The exterior material for a storage device according to claim 10, wherein the (B') phase-soluble elastomer is a hydrogenated styrene-based elastomer, and the (C) non-phase-soluble elastomer is a styrene-based elastomer. The exterior material for a power storage device according to any one of claims 10 to 12, wherein the sealant layer is formed of a plurality of layers, and among the plurality of layers forming the sealant layer, the sealant layer has the The second adhesive layer or the layer on the opposite side of the adhesive resin layer as a main surface is a layer formed of a resin composition containing the aforementioned (A) propylene-ethylene random copolymer. And a resin composition not containing the (B')-compatible elastomer and the (C) non-phase-soluble elastomer; or the (A) propylene-ethylene random copolymer and the (B')-compatible system Elastomer, and does not contain The above (C) is a non-miscible elastic resin composition. The exterior material for a storage battery device according to any one of claims 10 to 13, wherein the metal foil layer and the sealant layer are passed through the adhesive resin layer, and the adhesive resin layer contains an adhesive resin composition and Irregularly constructed polypropylene and/or propylene-alpha olefin copolymer. The exterior material for a power storage device according to any one of claims 10 to 13, wherein the metal foil layer and the sealant layer are permeable to the second adhesive layer, and the second adhesive layer comprises: acid-modified poly An olefin resin; and a compound selected from the group consisting of a polyfunctional isocyanate compound, a glycidyl compound, a carboxyl group, and At least one compound of the group of oxazoline group compounds. The exterior material for an electrical storage device according to any one of claims 10 to 15, wherein the anticorrosive treatment layer contains cerium oxide, 1 to 100 parts by mass of phosphoric acid or phosphate, and a cation with respect to 100 parts by mass of the cerium oxide. Polymer. The exterior material for a storage battery device according to any one of claims 10 to 15, wherein the anticorrosive treatment layer is formed by subjecting the metal foil layer to a chemical conversion treatment, and comprises a cationic polymer.